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[Display omitted] • Neutrophilic inflammation is a critical pathogenic hallmark in ARDS. • Ribociclib, a clinically-used CDK4/6 inhibitor, acts as a novel PDE4 inhibitor to regulate neutrophilic inflammation. • Ribociclib shows therapeutic potential in ARDS. • The drug repurposing of ribociclib provides a promising opportunity for neutrophil-associated diseases, including ARDS. Overwhelming neutrophil activation and oxidative stress significantly contribute to acute respiratory distress syndrome (ARDS) pathogenesis. However, the potential of repurposing ribociclib, a cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor used clinically in cancer treatment, for treating neutrophilic ARDS remains uncertain. This study illustrated the ability and underlying mechanism of ribociclib for treating ARDS and neutrophilic inflammation. Primary human neutrophils were used to determine the therapeutic effects of ribociclib on respiratory bursts, chemotactic responses, and inflammatory signaling. In vitro and silico analyses were performed to determine the underlying molecular mechanisms. The potential of ribociclib repurposing was evaluated using an in vivo ARDS model in lipopolysaccharide (LPS)-primed mice. We found that treatment using ribociclib markedly limited overabundant oxidative stress (reactive oxygen species [ROS]) production and chemotactic responses (integrin levels and adhesion) in activated human neutrophils. Ribociclib was also shown to act as a selective inhibitor of phosphodiesterase 4 (PDE4), thereby promoting the cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) pathway, leading to the inhibition of extracellular signal-regulated kinase (ERK), c-Jun N -terminal kinase (JNK) phosphorylation, and calcium influx. Notably, prophylactic administration and post-treatment with ribociclib ameliorated neutrophil infiltration, lung inflammation, accumulation of oxidative stress, pulmonary destruction, and mortality in mice with LPS-induced ARDS. We demonstrated for the first time that ribociclib serves as a novel PDE4 inhibitor for treating neutrophilic inflammation and ARDS. The repurposing ribociclib and targeting neutrophilic PDE4 offer a potential off-label alternative for treating lung lesions and other inflammatory conditions. [ABSTRACT FROM AUTHOR]

• Loss of lung function during late childhood remains a problem for patients with cystic fibrosis. • Respiratory exacerbations requiring hospitalization in early life appear to me drivers of loss of lung function later in childhood. • In this study we confirm that respiratory exacerbations requiring hospitalization in the first 5 years of life, together with markers of neutrophilic inflammation drive loss of lung function from childhood to adolescence. Despite improvements in general health and life expectancy in people with cystic fibrosis (CF), lung function decline continues unabated during adolescence and early adult life. We examined factors present at age 5-years that predicted lung function decline from childhood to adolescence in a longitudinal study of Australasian children with CF followed from 1999 to 2017. Lung function trajectories were calculated for 119 children with CF from childhood (median 5.0 [25%-75%=5.0–5.1]) years) to early adolescence (median 12.5 [25%-75%=11.4–13.8] years). Lung function fell progressively, with mean (standard deviation) annual change -0.105 (0.049) for forced vital capacity (FVC) Z-score (p <0.001), -0.135 (0.048) for forced expiratory volume in 1-second (FEV 1) Z-score (p <0.001), -1.277 (0.221) for FEV 1 /FVC% (p <0.001), and -0.136 (0.052) for forced expiratory flow between 25% and 75% of FVC Z-score (p <0.001). Factors present in childhood predicting lung function decline to adolescence, in multivariable analyses, were hospitalisation for respiratory exacerbations in the first 5-years of life (FEV 1 /FVC p = 0.001, FEF 25–75 p = 0.01) and bronchoalveolar lavage neutrophil elastase activity (FEV 1 /FVC% p = 0.001, FEV 1 p = 0.05, FEF 25–75 p = 0.02). No examined factor predicted a decline in the FVC Z-score. Action in the first 5-years of life to prevent and/or treat respiratory exacerbations and counteract neutrophilic inflammation in the lower airways may reduce lung function decline in children with CF, and these should be targets of future research. [ABSTRACT FROM AUTHOR]

Abstract Background Little is known about the role of interleukin (IL)-1 in the pathogenesis of cystic fibrosis (CF) lung disease. This study investigated the relationship between IL-1 signalling, neutrophilic inflammation and structural lung changes in children with CF. Methods Bronchoalveolar lavage fluid (BALf) from 102 children with CF were used to determine IL-1α, IL-1β, IL-8 levels and neutrophil elastase (NE) activity, which were then correlated to structural lung changes observed on chest computed tomography (CT) scans. Results IL-1α and IL-1β were detectable in BAL in absence of infection, increased in the presence of bacterial infection and correlated with IL-8 (p < 0.0001), neutrophils (p < 0.0001) and NE activity (p < 0.01 and p < 0.001). IL-1α had the strongest association with structural lung disease (p < 0.01) in the absence of infection (uninfected: p < 0.01 vs. infected: p = 0.122). Conclusion Our data associates IL-1α with early structural lung damage in CF and suggests this pathway as a novel anti-inflammatory target. [ABSTRACT FROM AUTHOR]

Corticosteroid resistance, progressive lung function decline, and frequent asthma exacerbations are the hallmarks of neutrophilic asthma (NA). However, the potential contributors and their mechanisms of NA aggravation have not yet been fully clarified. This study was conducted to assess the precise mechanism and inflammatory effects of endocrine-disrupting chemicals using mono-n-butyl phthalate (MnBP) on an NA model. BALB/c mice from normal control and LPS/OVA-induced NA groups were treated with or without MnBP. The effects of MnBP on the airway epithelial cells (AECs), macrophages (Mφ), and neutrophils were investigated in vitro and in vivo. NA mice exposed to MnBP had significantly increased airway hyperresponsiveness, total and neutrophil cell counts in the bronchoalveolar lavage fluid, and the percentage of M1Mφ in the lung tissues compared to those non-exposed to MnBP. In in vitro study, MnBP induced the human neutrophil activation to release neutrophil DNA extracellular traps, Mφ polarizing toward M1Mφ, and AEC damage. Treatment with hydroxychloroquine (an autophagy inhibitor) reduced the effects of MnBP in vivo and in vitro. The results of our study suggest that MnBP exposure may increase the risk of neutrophilic inflammation in severe asthma and autophagy pathway-targeted therapeutics can help control MnBP-induced harmful effects in asthma. Suggested pathophysiological pathways of MnBP. Figures were drawn by using pictures from Servier Medical Art (https://smart.servier.com/), licensed under a Creative Commons Attribution 3.0 Unported License (https://creativecommons.org/licenses/by/3.0/). AECs, airway epithelial cells; BALF, bronchoalveolar lavage fluid; dsDNA, double-stranded DNA; HCQ, hydroxychloroquine; LPS, lipopolysaccharides; Mφ, macrophages; MnBP, mono-n-butyl phthalate; MPO, myeloperoxidase; NE, neutrophil elastase; OVA, ovalbumin; TNF-α, tumour necrosis factor α. [Display omitted] • The exposure to MnBP enhances neutrophilic inflammation in asthma in vivo. • Administration of MnBP activates autophagy-related proteins in lung tissue in vivo. • MnBP induces the disruptions of tight junctions and macrophage activation in vitro. • MnBP activates autophagy pathway inducing neutrophil activation in vitro. • Autophagy inhibitor (HCQ) may inhibit the harmful effects of MnBP. [ABSTRACT FROM AUTHOR]

Background Asthma is classified according to severity and inflammatory phenotype and is likely to be distinguished by specific microRNA (miRNA) expression profiles. Objective We sought to associate miRNA expression in sputum supernatants with the inflammatory cell profile and disease severity in asthmatic patients. Methods We investigated miRNA expression in sputum supernatants of 10 healthy subjects, 17 patients with mild-to-moderate asthma, and 9 patients with severe asthma using high-throughput, stem-loop, reverse transcriptase quantitative real-time PCR miRNA expression profiling (screening cohort, n = 36). Differentially expressed miRNAs were validated in an independent cohort (n = 60; 10 healthy subjects and 50 asthmatic patients). Cellular miRNA origin was examined by using in situ hybridization and reverse transcriptase quantitative real-time PCR. The functional role of miRNAs was assessed by using in silico analysis and in vitro transfecting miRNA mimics in human bronchial epithelial cells. Results In 2 independent cohorts expression of miR-629-3p, miR-223-3p, and miR-142-3p was significantly upregulated in sputum of patients with severe asthma compared with that in healthy control subjects and was highest in patients with neutrophilic asthma. Expression of the 3 miRNAs was associated with sputum neutrophilia, and miR-223-3p and miR-142-3p expression was associated also with airway obstruction (FEV 1 /forced vital capacity). Expression of miR-629-3p was localized in the bronchial epithelium, whereas miR-223-3p and miR-142-3p were expressed in neutrophils, monocytes, and macrophages. Transfecting human bronchial epithelial cells with miR-629-3p mimic induced epithelial IL-8 mRNA and protein expression. IL-1β and IL-8 protein levels were significantly increased in sputum of patients with severe asthma and were positively associated with sputum neutrophilia. Conclusions Expression of miR-223-3p, miR-142-3p, and miR-629-3p is increased in sputum of patients with severe asthma and is linked to neutrophilic airway inflammation, suggesting that these miRNAs contribute to this asthma inflammatory phenotype. [ABSTRACT FROM AUTHOR]

Streptococcus pneumoniae is a pathogen of global morbidity and mortality. Pneumococcal pneumonia can lead to systemic infections associated with high rates of mortality. We find that, upon pneumococcal infection, pulmonary Treg cells are activated and have upregulated TNFR2 expression. TNFR2-deficient mice have compromised Treg cell responses and highly activated IL-17A-producing γδ T cell (γδT17) responses, resulting in significantly enhanced neutrophil infiltration, tissue damage, and rapid development of bacteremia, mirroring responses in Treg cell-depleted mice. Deletion of total Treg cells predominantly activate IFNγ-T cell responses, whereas adoptive transfer of TNFR2+ Treg cells specifically suppress the γδT17 response, suggesting a targeted control of γδT17 activation by TNFR2+ Treg cells. Blocking IL-17A at early stage of infection significantly reduces bacterial blood dissemination and improves survival in TNFR2-deficient mice. Our results demonstrate that TNFR2 is critical for Treg cell-mediated regulation of pulmonary γδT17-neutrophil axis, with impaired TNFR2+ Treg cell responses increasing susceptibility to disease. [Display omitted] • Pneumococcus activates lung Treg cells with upregulated TNFR2 • TNFR2+ Treg cells are associated with resistance to pneumococcal infection • TNFR2+ Treg cells specifically suppress pulmonary IL-17A-producing γδ T cells • Dysregulated γδT17 response correlates with excessive neutrophil influx to the lung Xu et al. show that pulmonary Treg cells are activated by pneumococci via TNFR2, and lack of Treg cells or TNFR2 promotes bacterial dissemination from lungs to blood. TNFR2+ Treg cells confer resistance to pneumococcal infection by controlling pulmonary γδT17 cell responses and neutrophil recruitment. [ABSTRACT FROM AUTHOR]

Inflammation is a decisive pathophysiologic mechanism of particle toxicity and accumulation of neutrophils in the lung is believed to be a crucial step in this process. This study describes an in vitro model for investigations of the chemotactic attraction of neutrophils in response to particles using permanent cell lines. We challenged NR8383 rat macrophages with particles that were characterized concerning chemical nature, crystallinity, and size distribution in the dry state and in the culture medium. The cell supernatants were used to investigate migration of differentiated human leukemia cells (dHL-60 cells). The dose range for the tests was determined using an impedance-based Real-Time Cell Analyzer. The challenge of NR8383 cells with 32–96 μg cm −2 coarse and nanosized particles resulted in cell supernatants which induced strong and dose-dependent migration of dHL-60 cells. Quartz caused the strongest effects – exceeding the positive control “fetal calf serum” (FCS) several-fold, followed by silica, rutile, carbon black, and anatase. BaSO 4 served as inert control and induced no cell migration. Particles caused NR8383 cells to secrete chemotactic compounds. The assay clearly distinguished between the particles of different inflammatory potential in a highly reproducible way. Specificity of the test is suggested by negative results with BaSO 4 . [ABSTRACT FROM AUTHOR]

Highlights: [•] Toluene diisocyanate (TDI) was unequivocally identified as asthmagens in BN-rats. [•] The elicitation response on BAL-PMN was threshold-dose dependent. [•] The elicitation of asthma-like responses follow a concentration×time-relationship. [•] The human-equivalent dose–response was duplicated in rats. [•] The derived occupational exposure level (OEL) matches current standards. [ABSTRACT FROM AUTHOR]

Bronchial asthma (BA) is a heterogeneous chronic inflammatory disease of the airways. The majority of patients with mild to moderate BA develop Th2-biased eosinophilic pulmonary inflammation and respond well to corticosteroid treatment. However up to 10% of BA patients develop severe pathology, which is associated with neutrophilic inflammation and resistant to conventional corticosteroid therapy. Contrary to eosinophil-predominant airway inflammation neutrophilic BA is developed through Th1- and Th17-immune responses. However, the etiology of corticoid insensitive neutrophilic BA is still remains unclear. Therefore, in the current study we developed a mouse model of BA with predominant neutrophilic rather than eosinophilic pulmonary inflammation. BALB/c mice were immunized with the mixture of the ovalbumin allergen and Freund's adjuvant, followed by aerosol challenge with the same allergen mixed with E. coli lipopolysaccharide. As a result, mice developed the main BA manifestations: production of allergen specific IgE, development of airway hyperreactivity, airway remodeling and pulmonary neutrophilic inflammation. Moreover, this pathology developed through Th1- and Th17-dependent mechanisms and mice with induced neutrophilic BA phenotype responded poorly to dexamethasone treatment, that coincide to clinical observations. The established mouse model could be useful both for studying the pathogenesis and for testing novel approaches to control neutrophilic BA. [ABSTRACT FROM AUTHOR]

Introduction: In addition to emphysema alpha-1-antitrypsin deficiency (AATD) has been shown to be associated with several inflammatory conditions, including bronchiectasis, vasculitis, (in particular Wegener's granulomatosis), and panniculitis, suggesting neutrophil proteinases also play a role in their pathophysiology. However, it remains unknown whether other inflammatory diseases are also more prevalent in AATD than the general population. The current study describes the prevalence of other co-morbidities in AATD with particular emphasis on inflammatory bowel disease. Methods and results: The case notes of 651 PiZZ or PiZnull patients attending the UK national centre for AATD between 1996 and 2011 were reviewed. The prevalence of inflammatory bowel disease (1.5%) was higher than that predicted in the UK (0.4%). Ten patients had a confirmed diagnosis of ulcerative colitis, and 1 had Crohn's disease. In 2 cases there was a family history of inflammatory bowel disease and all but 1 patient were ex or never smokers. There was also a higher prevalence of hypothyroidism in this patient group than expected for the UK population - 26 cases (7.2% of females and 1.3% of males). Conclusions: The current study of the UK cohort of patients with AATD confirmed a higher prevalence of ulcerative colitis than would be expected in the general population, providing further evidence of a potential link between these 2 conditions. In addition, the data suggested a potential link between hypothyroidism and AATD. [ABSTRACT FROM AUTHOR]

Background: Despite data indicating a positive correlation between donor-specific anti-HLA antibodies (DSAs) and early development of bronchiolitis obliterans syndrome (BOS) in lung allografts, the role of an antibody-mediated process in acute and chronic lung allograft rejection has not been elucidated. In this study we evaluated pathologic features of transplant lung biopsies in patients with and without DSAs. Methods: Forty-one lung transplant biopsies from 41 patients at our institution were included in our study. The biopsy H&E slides were reviewed in a blinded fashion, and scored for presence of microvascular inflammation, acute rejection, bronchiolar inflammation and acute lung injury, as well as diffuse alveolar damage (DAD). Microvascular inflammation was graded by the presence of capillary neutrophils on a scale of 0 to 4+. For immunohistochemical analysis, the pattern and intensity of staining for C4d and C3d deposition were evaluated in airways and alveolar capillaries. Results: Histopathology suspicious for antibody-mediated rejection (AMR)—defined as≥2+ neutrophilic infiltration and/or DAD—were more common in DSA-positive cases than controls (11 of 16 vs 6 of 25, p<0.01). Evidence of allograft dysfunction was significantly more common among patients with both DSA and suspicious histopathology compared with controls (5 of 10 vs 3 of 25, p = 0.03). The combination of DSAs and histopathology suspicious for AMR was associated with both BOS (p = 0.002) and mortality (p = 0.03). Immunohistochemistry for C3d and C4d showed no correlation with each other, DSAs or histopathology. Conclusions: Grade 2+ neutrophilic infiltration is the histopathologic finding most closely related to DSAs with graft dysfunction and development of BOS in lung transplant recipients and may be a marker for AMR. [ABSTRACT FROM AUTHOR]

Abstract: We quantified TGF-β1 and acetylcholine (ACh) concentrations in induced sputum supernatants (ISSs) from 18 healthy controls (HC), 22 healthy smokers (HS) and 21 COPDs. ISSs from HC, HS and COPD as well as rhTGF-β1 were also tested in neutrophil adhesion and in mAChR2, mAChR3 and ChAT expression experiments in human bronchial epithelial cells (16-HBE). Finally, we evaluated the effects of Olodaterol (a novel inhaled β2-adrenoceptor agonist) and Tiotropium Spiriva®, alone or in combination, on neutrophil adhesion and mAChRs and ChAT expression in stimulated 16-HBE. The results showed that 1) TGF-β1 and ACh concentrations are increased in ISSs from COPD in comparison to HC and HS, and TGF-β1 in HS is higher than in HC; 2) ISSs from COPD and HS caused increased neutrophil adhesion to 16-HBE when compared to ISSs from HC. The effect of ISSs from COPD was significantly reduced by TGF-β1 depletion or by the pretreatment with Olodaterol or Tiotropium alone or in combination, while the effect of ISSs from HS was significantly reduced by the pretreatment with Olodaterol alone; 3) mAChR2, mAChR3 and ChAT expression was increased in 16-HBE stimulated with ISSs from COPD and TGF-β1 depletion significantly reduced this effect on mAChR3 and ChAT expression; 4) rhTGF-β1 increased mAChR2, mAChR3 and ChAT expression in 16-HBE; 5) Olodaterol did not affect the expression of mAChRs and ChAT in 16-HBE. Our findings support the use of β2 long-acting and anticholinergic drugs to control the bronchoconstriction and TGF-β1-mediated neutrophilic inflammation in COPD. [Copyright &y& Elsevier]

Summary: Background: High mobility group box 1 (HMGB-1), a ligand of the receptor for advanced glycation end products (RAGE), is an inflammatory mediator in various disorders. Its endogenous decoy inhibitor, endogenous secretory RAGE (esRAGE), prevents the activation of RAGE signaling, and imbalance between HMGB-1 and esRAGE is known to be a factor determining progression of chronic inflammatory diseases. Methods: We measured HMGB-1 and esRAGE levels in induced sputum from 44 asthmatic patients and 15 normal controls, and examined their correlations with asthma indices including pulmonary function test values and induced sputum indices. Results: HMGB-1 levels in induced sputum were significantly higher in asthmatic patients than in normal controls (p < 0.001). Similarly, esRAGE levels were significantly higher in asthmatic patients than in normal controls (p < 0.001). In asthmatic patients, HMGB-1 levels were inversely correlated with percentage of predicted forced expiratory volume in 1 s (%FEV1) and FEV1/forced vital capacity (FEV1/FVC). There was a significant increase in HMGB-1 level associated with severity of asthma (p < 0.001). However, there was no significant increase in esRAGE level associated with severity of asthma. In asthmatic patients, HMGB-1 levels were significantly correlated with percentage of neutrophils in induced sputum. Conclusions: Our findings suggest that the HMGB-1 is a mediator of neutrophilic airway inflammation in asthma and that imbalance between HMGB-1 and esRAGE is related to the severity of asthma. Combined measurement of HMGB-1 and esRAGE may be novel biomarkers in asthma with severe airflow limitation. [ABSTRACT FROM AUTHOR]

Abstract: Occupational exposure to polymeric diphenylmethane-diisocyanate (MDI), a known human asthmagen, can be attributed to two potential routes: the skin and the respiratory tract. While the skin as the route of sensitization was the focus of a previous investigation (Pauluhn, 2008), this paper describes a modified sensitization protocol using a 5-day inhalation exposure (days 0–4) of Brown Norway (BN) rats to two concentration×exposure time (C × t) relationships of 1000, 5000, and 10,000mg MDI/m3 ×min at exposure durations of either 10 or 360-min. Apart from the differences in the induction protocol, all other experimental variables remained identical. This was followed by four 30-min inhalation challenges to 40mg MDI/m3 on target days 20, 25, 50, and 65. After the last challenge, changes in breathing patterns delayed in onset were recorded and allergic lung inflammation was probed by bronchoalveolar lavage (BAL). In a subsequent study groups of rats were sensitized using the 10-min C × t protocol and challenged 3-times at 40mg MDI/m3. At the fourth challenge a dose-escalation regimen was used to determine the elicitation threshold on ‘asthmatic’ rats. Consistent with the skin-sensitization protocol, the most sensitive endpoints characterizing an allergic pulmonary inflammation were again BAL-neutrophils and physiological measurements showing respiratory changes delayed in onset. The dose-escalation challenge yielded an elicitation threshold of 5mg MDI-aerosol/m3 at 30min challenge duration. In topically sensitized rats this threshold was estimated to be 3mg/m3. In summary, these data suggest the C × t product of MDI-aerosol that triggers an elicitation response in ‘asthmatic’ rats is slightly below of that causing acute pulmonary irritation in naïve rats. The high concentration delivered to the respiratory tract during the 10-min exposure period elicited a more vigorous response than the similar C × t at 360min. Therefore, short high-level exposure patterns appear to bear a higher sensitizing potency than equal C × t products at longer exposure periods. Taking into account the respective differences in exposure intensities, the comparison of elicitation thresholds of BN rats sensitized by inhalation or skin exposure did not demonstrate essential differences. [Copyright &y& Elsevier]

Summary: Background: Airway dehydration is a potential trigger of bronchoconstriction in exercise-induced asthma; however, its role in stable asthma has not been explored. Using sputum percent solids, as an indicator of airway hydration, we sought relationships between airway hydration and other known markers of neutrophilic (TH1) and allergic (TH2) inflammation in stable asthma. Methods: Thirty-seven atopic subjects with stable asthma and 15 healthy controls underwent sputum induction. Sputum was analyzed for percent solids, cell counts, cellular and biochemical markers of inflammation and purines. Results: Sputum percent solids was significantly elevated in stable asthmatics vs. controls and positively correlated with markers of neutrophilic/TH1-type inflammation (neutrophils, IL-8 and AMP). Sputum percent solids were not correlated with markers of allergic/TH2-type inflammation. These data suggest a direct relationship between neutrophil inflammation and airway hydration in stable asthmatics. [Copyright &y& Elsevier]

Summary: Cigarette smoking causes inflammatory responses in the airways. However, not all smokers exhibit the development of airflow limitation. This study was designed to determine the implications of small airways inflammation in the development of airflow limitation in smokers by our newly explored method. Twenty-eight smokers (15 smokers without airflow limitation and 13 with airflow limitation) were included in this study. Levels of interleukin-8 (IL-8) and 8-isoprostane were measured in epithelial lining fluid (ELF) from central and peripheral airways separately collected using a bronchoscopic microsampling technique. 8-isoprostane levels in ELF from central or peripheral airways did not significantly differ between the two groups. However, these levels were markedly higher in peripheral than in central airways. Similarly, IL-8 levels in ELF from central airways did not significantly differ between the two groups. In smokers without airflow limitation, IL-8 levels were not higher in peripheral than in central airways. In contrast, in smokers with airflow limitation, IL-8 levels were significantly higher in peripheral airways. Moreover, in smokers with airflow limitation, 8-isoprostane levels in central or peripheral airways were not significantly correlated with FEV1. However, IL-8 levels in peripheral airways were inversely correlated with FEV1, though those levels in central airways were not. Thus our technique provides a novel method for ELF sampling from central or peripheral airways separately, and the preliminary evidence that support differences in oxidative stress and neutrophil chemotactic stimulus in these two locations. [Copyright &y& Elsevier]

Abstract: Brown Norway (BN) rats were topically sensitized to polymeric diphenylmethane-diisocyanate (MDI) and challenged with MDI-aerosol approximately every 2 weeks over a time period of 2 months. Half of the sensitized animals were pretreated with capsaicin for partial C-fiber defunctionalization. After the fourth challenge inflammatory and pro-inflammatory factors in bronchoalveolar lavage (BAL) fluid and cells and physiological delayed-onset breathing patterns were analyzed. The latter endpoint was examined in the capsaicin pretreated group before and after each challenge. Findings were compared against naïve but repeatedly MDI-challenged BN rats. BAL-neutrophils, -protein, and -LDH as well as lung weights were significantly increased in the MDI-sensitized and challenged rats relative to the naïve, challenged control rats. With regard to these endpoints, capsaicin pretreatment did not affect the responsiveness to MDI-aerosol. In contrast, pro-inflammatory cytokines, the Th2 cell cytokine IL-4, and the CC-chemokine MCP-1 were significantly increased in BAL-cells of capsaicin pretreated and MDI-sensitized rats, whilst in the normal MDI-sensitized rats markedly less pronounced changes (if any) occurred. In the former group, IL-4 and MCP-1 were also significantly increased in the lung draining lymph nodes. Time-related increased frequencies of delayed-onset responses were observed in MDI-sensitized rats after subsequent MDI-challenges, however, differences between capsaicin pretreated and normal rats were not found. Despite the remarkable differences between normal and capsaicin pre-treated rats in the concentrations of pro-inflammatory and Th1-/Th2-cell specific cytokines, the inflammatory endpoints in BAL as well as the physiological measurements did not identify appreciable differences amongst these groups. This study included an ancillary study addressing the analysis of the modulating effect of capsaicin pre-treatment of naïve Wistar rats exposed for single 6h to MDI-aerosol. The results indicated more pronounced changes on endpoints in the BAL-fluid of capsaicin-pretreated rats as compared to rats with intact C-fibers. This complex picture appears to suggest that C-fibers may modulate the allergic inflammatory response elicited by MDI-challenge. It appears that tachykinergic sensory C-fibers modulate the protective pathways against irritant-related lung inflammation and, similarly, also pro-inflammatory immunological factors modulating allergic inflammation. Although difficult to disentangle unequivocally the mechanisms involved, neuro-immunological factors may be important in triggering and maintaining this complex disease and cytokine/chemokine patterns may not necessarily predict the functional outcome of test. [Copyright &y& Elsevier]

In several non-infectious human diseases, such as ulcerous colitis, rheumatoid arthritis, chronic obstructive pulmonary disease (COPD), the extravasal recruitment of neutrophils plays a crucial role in the development of tissue damage, which, when persistent, can lead to the irreversible organ dysfunction. The neutrophil activation is controlled by a number of intracellular pathways, particularly by a cAMP-dependent protein kinase A (PKA) which also acts on phosphodiesterase IV (PDE4) gene stimulating the synthesis of this enzyme, able to transform cAMP to inactive AMP. PDE4 inhibitors enhance intracellular cAMP and decrease inflammatory cell activation. Several 3-cyclopentyloxy-4-methoxybenzaldehyde and 3-cyclopentyloxy-4-methoxybenzoic acid derivatives were synthesized and studied by us to evaluate their ability to inhibit the superoxide anion production in human neutrophils. These compounds were found able to inhibit the neutrophil activation and some of them increased the cAMP level on tumor necrosis factor-α-stimulated neutrophils. Moreover, they also inhibited selectively the human PDE4 enzyme, although they are less potent than the reference compound Rolipram. We report here synthesis, biological studies and some SAR considerations concerning the above mentioned compounds. [Copyright &y& Elsevier]

Gallbladder carcinoma is an uncommon malignancy with an overall 5-year survival of less than 5%. Gallbladder carcinoma has been strongly linked with cholelithiasis and chronic inflammation. Case reports and series have described cholecystitis with acute (neutrophilic) inflammation in association with gallbladder carcinoma, although a clear relationship to patient outcome has not been established. Our series included 8 cases of gallbladder carcinoma with high tumor-associated neutrophils (>25 per high power field) that were associated with shorter patient survival (Cox regression coefficient 6.2, p = 0.004) than age- and stage-matched controls. High tumor-associated neutrophils were not associated with gallbladder rupture/perforation or increased bacterial load measured by 16S PCR. Neutrophilic inflammation with gallbladder carcinoma correlates to shorter survival, independent of patient age and stage of carcinoma. The findings suggest that the degree of neutrophilic inflammation may have prognostic significance in specimens from patients with gallbladder carcinoma after cholecystectomy. Further studies with larger case numbers are needed to confirm and generalize these findings. • Significant correlations with decreased survival were found for cholecystectomy specimens for gallbladder carcinoma. • Neutrophilic inflammation with gallbladder carcinoma correlates to shorter survival, independent of patient age and stage of carcinoma. • High tumor-associated neutrophils were not associated with gallbladder rupture/perforation or increased bacterial load by 16S PCR. [ABSTRACT FROM AUTHOR]

[Display omitted] Psoriasis is a long-lasting inflammatory skin disease lacking proper cure. Dysregulated activation of neutrophils is a major pathogenic factor in psoriasis. Formyl peptide receptor 1 (FPR1) triggers neutrophil activation in response to bacteria- or mitochondria-derived N -formyl peptides, but its significance in neutrophilic psoriasis remains unknown. In this study, we discovered two derivatives of ursolic acid, 3β-hydroxyurs-12,18-dien-28-oic acid (randialic acid B, RAB) and 3β-hydroxyurs-12,19-dien-28-oic acid (tomentosolic acid, TA), as FPR1 inhibitors in human neutrophils with ability to suppress psoriatic symptoms in mice. Both RAB and TA, triterpenoids of traditional medicinal plant Ilex kaushue , selectively inhibited reactive oxygen species production, elastase release, and CD11b expression in human neutrophils activated by FPR1, but not non-FPR1 agonists. Importantly, RAB and TA inhibited the binding of N -formyl peptide to FPR1 in human neutrophils, neutrophil-like THP-1 cells, and hFPR1-transfected HEK293 cells, indicating FPR1 antagonism. Moreover, in assays induced by various concentrations of FPR1 agonist, both RAB and TA acted competitively for its binding to the FPR1 receptor. The FPR1-downstream signaling such as Ca2+ mobilisation and activation of Akt and MAPKs was also competitively inhibited. In addition, imiquimod-induced psoriasis-like symptoms, including epidermal hyperplasia, desquamation with scaling, neutrophil skin infiltration, and transepidermal water loss were significantly reduced by both RAB and TA. The results illustrate a possible role of human neutrophils FPR1 receptor in psoriasis-like inflammation. Accordingly, triterpenoids RAB and TA represent novel FPR1 antagonists and exhibit therapeutic potential for treating neutrophilic inflammatory skin diseases. [ABSTRACT FROM AUTHOR]

Lophatherum gracile Brongn. (L. gracile) has been long used in traditional herbal medicine to clinically clear heat, disinhibit dampness, and treat inflammation. However, the effect of L. gracile on the activation of human neutrophils remains unclear. The aim of current study is to investigate the anti-inflammatory properties of L. gracile extract (LGE) in N -formyl-methionyl-leucyl-phenylalanine (fMLF)-induced activation of human neutrophils. Superoxide anion generation and elastase release were estimated by spectrophotometry. A series of signaling pathways including mitogen-activated protein kinases (MAPKs) and protein kinase B (Akt), as well as calcium mobilization were studied by Western blot analysis and spectrofluorometry. Our experimental results indicated that the nontoxic dosage of LGE does-dependently inhibited the fMLF-induced superoxide anion (O 2 •−) generation, elastase release, CD11b expression, adhesion, and chemotactic migration in human neutrophils. LGE selectively inhibited the fMLF-induced phosphorylation of JNK but not p38, ERK, or Akt in human neutrophils. LGE also decreased the intracellular Ca2+ levels ([Ca2+] i) in fMLF-activated human neutrophils. However, a specific JNK inhibitor inhibited the fMLF-induced O 2 •− generation and CD11b expression, but it had no effect on [Ca2+] i in human neutrophils. LGE exhibited anti-inflammatory activities in fMLF-activated human neutrophils. The pharmacological mechanisms of LGE-repressed neutrophilic inflammation were through two independent pathways, JNK signaling and calcium mobilization. Our results suggested that LGE holds the potential to be developed as an anti-inflammatory botanical medicine. Image 1 [ABSTRACT FROM AUTHOR]

Suppression of airway inflammation with inhaled corticosteroids has been the key therapeutic approach for asthma for many years. Identification of inflammatory phenotypes in asthma has moreover led to important breakthroughs, e.g. with specific targeting of the IL-5 pathway as add-on treatment in difficult-to-treat eosinophilic asthma. However, the impact of interfering with the neutrophilic component in asthma is less documented and understood. This review provides an overview of established and recent insights with regard to the role of neutrophils in asthma, focusing on research in humans. We will describe the main drivers of neutrophilic responses in asthma, the heterogeneity in neutrophils and how they could contribute to asthma pathogenesis. Moreover we will describe findings from clinical trials, in which neutrophilic inflammation was targeted. It is clear that neutrophils are important actors in asthma development and play a role in exacerbations. However, more research is required to fully understand how modulation of neutrophil activity could lead to a significant benefit in asthma patients with airway neutrophilia. [ABSTRACT FROM AUTHOR]

Immuno-spin trapping detection of DNA radicals with the nitrone spin trap 5,5-dimethyl-1-pyrrloine N -oxide (DMPO) has made important contributions towards the understanding of DNA radicalization and genotoxicity at sites of inflammation. At sites of inflammation, one-electron oxidants and chloramines decay induce oxidation of genomic DNA, genotoxicity and cell transformation. Radicalization of DNA can result in either single- or double-strand breaks, or end-oxidation products at the sugar or bases. If not repaired, these modifications can lead to mutations and cell transformation. If trapped with DMPO, DNA-centered radical decay and subsequent formation of end-oxidation products are blocked. Herein we discuss recent literature regarding the use of immuno-spin trapping with DMPO to study DNA-centered radicals and their involvement in genotoxicity. This technique has shown the critical role of DNA radicalization in 8-oxo-dG formation and DNA strand breaks in isolated DNA, cells and in whole animals. Combination of technologies, including immuno-spin trapping and powerful chromatographic and sequencing techniques are needed to move forward the field towards the detection of specific genes that are susceptible to oxidative damage in cells located at sites of inflammation. This is important in order to provide novel information about genotoxicity mechanisms, as well as therapeutic possibilities of DMPO or its derivatives for preventing DNA-centered radical-mediated carcinogenesis. [ABSTRACT FROM AUTHOR]