S100A alarmins and thymic stromal lymphopoietin (TSLP) regulation in severe asthma following bronchial thermoplasty.

RATIONALE: Severe asthma affects a small proportion of asthmatics but represents a significant healthcare challenge. Bronchial thermoplasty (BT) is an interventional treatment approach preconized for uncontrolled severe asthma after considering biologics therapy. It was showed that BT long-lastingly improves asthma control. These improvements seem to be related to the ability of BT to reduce airway smooth muscle remodeling, reduce the number of nerve fibers and to modulate bronchial epithelium integrity and behavior. Current evidence suggest that BT downregulates epithelial mucins expression, cytokine production and metabolic profile. Despite these observations, biological mechanisms explaining asthma control improvement post-BT are still not well understood. OBJECTIVES: To assess whether BT affects gene signatures in bronchial epithelial cells (BECs). METHODS: In this study we evaluated the transcriptome of cultured bronchial epithelial cells (BECs) of severe asthmatics obtained pre- and post-BT treatment using microarrays. We further validated gene and protein expressions in BECs and in bronchial biopsies with immunohistochemistry pre- and post-BT treatment. MEASUREMENTS AND MAIN RESULTS: Transcriptomics analysis revealed that a large portion of differentially expressed genes (DEG) was involved in anti-viral response, anti-microbial response and pathogen induced cytokine storm signaling pathway. S100A gene family stood out as five members of this family where consistently downregulated post-BT. Further validation revealed that S100A7, S100A8, S100A9 and their receptor (RAGE, TLR4, CD36) expressions were highly enriched in severe asthmatic BECs. Further, these S100A family members were downregulated at the gene and protein levels in BECs and in bronchial biopsies of severe asthmatics post-BT. TLR4 and CD36 protein expression were also reduced in BECs post-BT. Thymic stromal lymphopoietin (TSLP) and human ß-defensin 2 (hBD2) were significantly decreased while no significant change was observed in IL-25 and IL-33. CONCLUSIONS: These data suggest that BT might improve asthma control by downregulating epithelial derived S100A family expression and related downstream signaling pathways.

The reduction of airway smooth muscle by bronchial thermoplasty stands the test of time.

Airway smooth muscle ablation induced by thermoplasty is maintained for >10 years along with the improvements in asthma control https://bit.ly/3nGqQSP.

Bronchial thermoplasty attenuates bronchodilator responsiveness.

INTRODUCTION: Bronchial thermoplasty is an effective intervention to improve respiratory symptoms and to reduce the rate of exacerbations in uncontrolled severe asthma. A reduction in airway smooth muscle is arguably the most widely discussed mechanisms accounting for these clinical benefits. Yet, this smooth muscle reduction should also translate into an impaired response to bronchodilator drugs. This study was designed to address this question. METHODS: Eight patients with clinical indication for thermoplasty were studied. They were uncontrolled severe asthmatics despite optimal environmental control, treatment of comorbidities, and the use of high-dose inhaled corticosteroids and long-acting ß2-agonists. Lung function measured by spirometry and respiratory mechanics measured by oscillometry were examined pre- and post-bronchodilator (salbutamol, 400 µg), both before and at least 1 year after thermoplasty. RESULTS: Consistent with previous studies, thermoplasty yielded no benefits in terms of baseline lung function and respiratory mechanics, despite improving symptoms based on two asthma questionnaires (ACQ-5 and ACT-5). The response to salbutamol was also not affected by thermoplasty based on spirometric readouts, including forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio. However, a significant interaction was observed between thermoplasty and salbutamol for two oscillometric readouts, namely reactance at 5 Hz (Xrs5) and reactance area (Ax), showing an attenuated response to salbutamol after thermoplasty. CONCLUSIONS: Thermoplasty attenuates the response to a bronchodilator. We argue that this result is a physiological proof of therapeutic efficacy, consistent with the well-described effect of thermoplasty in reducing the amount of airway smooth muscle.

Human and Mouse Eosinophils Differ in Their Ability to Biosynthesize Eicosanoids, Docosanoids, the Endocannabinoid 2-Arachidonoyl-glycerol and Its Congeners.

High eosinophil (EOS) counts are a key feature of eosinophilic asthma. EOS notably affect asthmatic response by generating several lipid mediators. Mice have been utilized in hopes of defining new pharmacological targets to treat asthma. However, many pinpointed targets in mice did not translate into clinics, underscoring that key differences exist between the two species. In this study, we compared the ability of human (h) and mouse (m) EOS to biosynthesize key bioactive lipids derived from arachidonic acid (AA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). hEOS were isolated from the blood of healthy subjects and mild asthmatics, while mEOSs were differentiated from the bone marrow. EOSs were treated with fatty acids and lipid mediator biosynthesis assessed by LC-MS/MS. We found that hEOS biosynthesized leukotriene (LT) C4 and LTB4 in a 5:1 ratio while mEOS almost exclusively biosynthesized LTB4. The biosynthesis of the 15-lipoxygenase (LO) metabolites 15-HETE and 12-HETE also differed, with a 15-HETE:12-HETE ratio of 6.3 for hEOS and 0.727 for mEOS. EOS biosynthesized some specialized pro-resolving mediators, and the levels from mEOS were 9-times higher than those of hEOS. In contrast, hEOS produced important amounts of the endocannabinoid 2-arachidonoyl-glycerol (2-AG) and its congeners from EPA and DHA, a biosynthetic pathway that was up to ~100-fold less prominent in mEOS. Our data show that hEOS and mEOS biosynthesize the same lipid mediators but in different amounts. Compared to asthmatics, mouse models likely have an amplified involvement of LTB4 and specialized pro-resolving mediators and a diminished impact of the endocannabinoid 2-arachidonoyl-glycerol and its congeners.

Bronchial Thermoplasty in Patients With Severe Asthma at 5 Years: The Post-FDA Approval Clinical Trial Evaluating Bronchial Thermoplasty in Severe Persistent Asthma Study.

BACKGROUND: Bronchial thermoplasty is a device-based treatment for subjects ≥ 18 years of age with severe asthma poorly controlled with inhaled corticosteroids and long-acting beta-agonists. The Post-FDA Approval Clinical Trial Evaluating Bronchial Thermoplasty in Severe Persistent Asthma (PAS2) study collected data on patients with severe asthma undergoing this procedure. RESEARCH QUESTION: What are the 5-year efficacy and safety results in patients with severe asthma who have undergone bronchial thermoplasty? STUDY DESIGN AND METHODS: This was a prospective, open-label, observational, multicenter study conducted in the United States and Canada. Subjects 18 to 65 years of age who were taking inhaled corticosteroids ≥ 1,000 µg/d (beclomethasone or equivalent) and long-acting beta-agonists ≥ 80 µg/d (salmeterol or equivalent) were included. Severe exacerbations, hospitalization, ED visits, and medication usage were evaluated for the 12 months prior to and at years 1 through 5 posttreatment. Spirometry was evaluated at baseline and at years 1 through 5 posttreatment. RESULTS: A total of 284 subjects were enrolled at 27 centers; 227 subjects (80%) completed 5 years of follow-up. By year 5 posttreatment, the proportion of subjects with severe exacerbations, ED visits, and hospitalizations was 42.7%, 7.9%, and 4.8%, respectively, compared with 77.8%, 29.4%, and 16.1% in the 12 months prior to treatment. The proportion of subjects on maintenance oral corticosteroids decreased from 19.4% at baseline to 9.7% at 5 years. Analyses of subgroups based on baseline clinical and biomarker characteristics revealed a statistically significant clinical improvement among all subgroups. INTERPRETATION: Five years after treatment, subjects experienced decreases in severe exacerbations, hospitalizations, ED visits, and corticosteroid exposure. All subgroups demonstrated clinically significant improvement, suggesting that bronchial thermoplasty improves asthma control in different asthma phenotypes. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov; No.: NCT01350336; URL: www. CLINICALTRIALS: gov.

Biosynthesis of the Novel Endogenous 15-Lipoxygenase Metabolites N-13-Hydroxy-octodecadienoyl-ethanolamine and 13-Hydroxy-octodecadienoyl-glycerol by Human Neutrophils and Eosinophils.

The endocannabinoids 2-arachidonoyl-glycerol and N-arachidonoyl-ethanolamine are lipids regulating many physiological processes, notably inflammation. Endocannabinoid hydrolysis inhibitors are now being investigated as potential anti-inflammatory agents. In addition to 2-arachidonoyl-glycerol and N-arachidonoyl-ethanolamine, the endocannabinoidome also includes other monoacylglycerols and N-acyl-ethanolamines such as 1-linoleoyl-glycerol (1-LG) and N-linoleoyl-ethanolamine (LEA). By increasing monoacylglycerols and/or N-acyl-ethanolamine levels, endocannabinoid hydrolysis inhibitors will likely increase the levels of their metabolites. Herein, we investigated whether 1-LG and LEA were substrates for the 15-lipoxygenase pathway, given that both possess a 1Z,4Z-pentadiene motif, near their omega end. We thus assessed how human eosinophils and neutrophils biosynthesized the 15-lipoxygenase metabolites of 1-LG and LEA. Linoleic acid (LA), a well-documented substrate of 15-lipoxygenases, was used as positive control. N-13-hydroxy-octodecadienoyl-ethanolamine (13-HODE-EA) and 13-hydroxy-octodecadienoyl-glycerol (13-HODE-G), the 15-lipoxygenase metabolites of LEA and 1-LG, were synthesized using Novozym 435 and soybean lipoxygenase. Eosinophils, which express the 15-lipoxygenase-1, metabolized LA, 1-LG, and LEA into their 13-hydroxy derivatives. This was almost complete after five minutes. Substrate preference of eosinophils was LA > LEA > 1-LG in presence of 13-HODE-G hydrolysis inhibition with methyl-arachidonoyl-fluorophosphonate. Human neutrophils also metabolized LA, 1-LG, and LEA into their 13-hydroxy derivatives. This was maximal after 15-30 s. Substrate preference was LA ≫ 1-LG > LEA. Importantly, 13-HODE-G was found in humans and mouse tissue samples. In conclusion, our data show that human eosinophils and neutrophils metabolize 1-LG and LEA into the novel endogenous 15-lipoxygenase metabolites 13-HODE-G and 13-HODE-EA. The full biological importance of 13-HODE-G and 13-HODE-EA remains to be explored.

Prioritization of candidate causal genes for asthma in susceptibility loci derived from UK Biobank.

To identify candidate causal genes of asthma, we performed a genome-wide association study (GWAS) in UK Biobank on a broad asthma definition (n = 56,167 asthma cases and 352,255 controls). We then carried out functional mapping through transcriptome-wide association studies (TWAS) and Mendelian randomization in lung (n = 1,038) and blood (n = 31,684) tissues. The GWAS reveals 72 asthma-associated loci from 116 independent significant variants (PGWAS < 5.0E-8). The most significant lung TWAS gene on 17q12-q21 is GSDMB (PTWAS = 1.42E-54). Other TWAS genes include TSLP on 5q22, RERE on 1p36, CLEC16A on 16p13, and IL4R on 16p12, which all replicated in GTEx lung (n = 515). We demonstrate that the largest fold enrichment of regulatory and functional annotations among asthma-associated variants is in the blood. We map 485 blood eQTL-regulated genes associated with asthma and 50 of them are causal by Mendelian randomization. Prioritization of druggable genes reveals known (IL4R, TSLP, IL6, TNFSF4) and potentially new therapeutic targets for asthma.

Chemokines and eicosanoids fuel the hyperinflammation within the lungs of patients with severe COVID-19.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can lead to a variety of clinical outcomes, ranging from the absence of symptoms to severe acute respiratory disease and ultimately death. A feature of patients with severe coronavirus disease 2019 (COVID-19) is the abundance of inflammatory cytokines in the blood. Elevated levels of cytokines are predictive of infection severity and clinical outcome. In contrast, studies aimed at defining the driving forces behind the inflammation in lungs of subjects with severe COVID-19 remain scarce. OBJECTIVE: Our aim was to analyze and compare the plasma and bronchoalveolar lavage (BAL) fluids of patients with severe COVID-19 (n = 45) for the presence of cytokines and lipid mediators of inflammation (LMIs). METHODS: Cytokines were measured by using Luminex multiplex assay, and LMIs were measured by using liquid chromatography-tandem mass spectrometry. RESULTS: We revealed high concentrations of numerous cytokines, chemokines, and LMIs in the BAL fluid of patients with severe COVID-19. Of the 13 most abundant mediators in BAL fluid, 11 were chemokines, with CXCL1 and CXCL8 being 200 times more abundant than IL-6 and TNF-α. Eicosanoid levels were also elevated in the lungs of subjects with severe COVID-19. Consistent with the presence chemotactic molecules, BAL fluid samples were enriched for neutrophils, lymphocytes, and eosinophils. Inflammatory cytokines and LMIs in plasma showed limited correlations with those present in BAL fluid, arguing that circulating inflammatory molecules may not be a reliable proxy of the inflammation occurring in the lungs of patients with severe COVID-19. CONCLUSIONS: Our findings indicate that hyperinflammation of the lungs of patients with severe COVID-19 is fueled by excessive production of chemokines and eicosanoids. Therapeutic strategies to dampen inflammation in patients with COVID-19 should be tailored accordingly.

High levels of eicosanoids and docosanoids in the lungs of intubated COVID-19 patients.

Severe acute respiratory syndrome coronavirus 2 is responsible for coronavirus disease 2019 (COVID-19). While COVID-19 is often benign, a subset of patients develops severe multilobar pneumonia that can progress to an acute respiratory distress syndrome. There is no cure for severe COVID-19 and few treatments significantly improved clinical outcome. Dexamethasone and possibly aspirin, which directly/indirectly target the biosynthesis/effects of numerous lipid mediators are among those options. Our objective was to define if severe COVID-19 patients were characterized by increased bioactive lipids modulating lung inflammation. A targeted lipidomic analysis of bronchoalveolar lavages (BALs) by tandem mass spectrometry was done on 25 healthy controls and 33 COVID-19 patients requiring mechanical ventilation. BALs from severe COVID-19 patients were characterized by increased fatty acids and inflammatory lipid mediators. There was a predominance of thromboxane and prostaglandins. Leukotrienes were also increased, notably LTB4 , LTE4 , and eoxin E4 . Monohydroxylated 15-lipoxygenase metabolites derived from linoleate, arachidonate, eicosapentaenoate, and docosahexaenoate were also increased. Finally yet importantly, specialized pro-resolving mediators, notably lipoxin A4 and the D-series resolvins, were also increased, underscoring that the lipid mediator storm occurring in severe COVID-19 involves pro- and anti-inflammatory lipids. Our data unmask the lipid mediator storm occurring in the lungs of patients afflicted with severe COVID-19. We discuss which clinically available drugs could be helpful at modulating the lipidome we observed in the hope of minimizing the deleterious effects of pro-inflammatory lipids and enhancing the effects of anti-inflammatory and/or pro-resolving lipid mediators.

Safety and effectiveness of bronchial thermoplasty after 10 years in patients with persistent asthma (BT10+): a follow-up of three randomised controlled trials.

BACKGROUND: Bronchial thermoplasty is an endoscopic treatment for uncontrolled asthma. Previous randomised clinical trials have shown that bronchial thermoplasty reduces severe exacerbations in people with asthma. However, the long-term efficacy and safety of bronchial thermoplasty beyond 5 years is unknown. The BT10+ study aimed to investigate the efficacy and safety of bronchial thermoplasty after 10 or more years of follow-up. METHODS: BT10+ was an international, multicentre, follow-up study of participants who were previously enrolled in the AIR, RISA, and AIR2 trials and who had 10 or more years of follow-up since bronchial thermoplasty treatment. Data on patient demographics, quality of life, lung function, CT scans (AIR2 participants only), severe exacerbations, and health-care use during the previous year were collected at the BT10+ 10-year outcomes study visit. The primary effectiveness endpoint was durability of the thermoplasty treatment effect, determined by comparing the proportion of participants who had severe exacerbations during the first and fifth years after bronchial thermoplasty treatment with the proportion of participants who had severe exacerbations during the 12-month period before the BT10+ visit. The primary safety endpoint was the absence of clinically significant post-treatment respiratory image changes after bronchial thermoplasty, defined as bronchiectasis or bronchial stenosis as confirmed by pulmonary volumetric high-resolution CT scan at the BT10+ visit (AIR2 participants only). All analyses were done on an intention-to-treat basis. The trial is registered with ClinicalTrials.gov, NCT03243292. The last patient was enrolled on Dec 11, 2018. The last patient completed follow-up on Jan 10, 2019. FINDINGS: The BT10+ study enrolled 192 (45%) of the 429 participants who were enrolled in the AIR, RISA, and AIR2 trials. The BT10+ participants comprised 136 who received bronchial thermoplasty (52% of the 260 participants who received bronchial thermoplasty in the original trials), and 56 sham or control participants (33% of 169 from the original trials). 18 (32%) sham or control participants received bronchial thermoplasty after the previous trials concluded. The participants included in BT10+ were followed for 10·8-15·6 years (median 12·1 years) post-treatment. Baseline characteristics were similar between participants enrolled in BT10+ and those not enrolled. Participants treated with bronchial thermoplasty had similar proportions of severe exacerbations at the BT10+ visit (34 [25%] of 136 participants) compared with 1 year (33 [24%] of 135 participants; difference 0·6%, 95% CI -9·7 to 10·8) and 5 years (28 [22%] of 130 participants; difference 3·5%, -6·7% to 13·6) after treatment. Quality of life measurements and spirometry were similar between year 1, year 5, and the BT10+ visit. At the BT10+ study visit, pulmonary high-resolution CT scans from AIR2 participants treated with bronchial thermoplasty showed that 13 (13%) of 97 participants had bronchiectasis. When compared with baseline high-resolution CT scans, six (7%) of 89 participants treated with bronchial thermoplasty who did not have bronchiectasis at baseline had developed bronchiectasis after treatment (5 classified as mild, 1 classified as moderate). Participants treated with bronchial thermoplasty after the original study and participants in the sham or control group also had reductions in severe exacerbations at the BT10+ visit compared with baseline. INTERPRETATION: Our findings suggest that efficacy of bronchial thermoplasty is sustained for 10 years or more, with an acceptable safety profile. Therefore, bronchial thermoplasty is a long-acting therapeutic option for patients with asthma that remains uncontrolled despite optimised medical treatment. FUNDING: Boston Scientific.

Endocannabinoid hydrolysis inhibition unmasks that unsaturated fatty acids induce a robust biosynthesis of 2-arachidonoyl-glycerol and its congeners in human myeloid leukocytes.

The endocannabinoid (eCB) 2-arachidonoyl-gycerol (2-AG) modulates immune responses by activating cannabinoid receptors or through its multiple metabolites, notably eicosanoids. Thus, 2-AG hydrolysis inhibition might represent an interesting anti-inflammatory strategy that would simultaneously increase the levels of 2-AG and decrease those of eicosanoids. Accordingly, 2-AG hydrolysis inhibition increased 2-AG half-life in neutrophils. Under such setting, neutrophils, eosinophils, and monocytes synthesized large amounts of 2-AG and other monoacylglycerols (MAGs) in response to arachidonic acid (AA) and other unsaturated fatty acids (UFAs). Arachidonic acid and UFAs were ~1000-fold more potent than G protein-coupled receptor (GPCR) agonists. Triascin C and thimerosal, which, respectively, inhibit fatty acyl-CoA synthases and acyl-CoA transferases, prevented the UFA-induced MAG biosynthesis, implying glycerolipid remodeling. 2-AG and other MAG biosynthesis was preceded by that of the corresponding lysophosphatidic acid (LPA). However, we could not directly implicate LPA dephosphorylation in MAG biosynthesis. While GPCR agonists poorly induced 2-AG biosynthesis, they inhibited that induced by AA by 25%-50%, suggesting that 2-AG biosynthesis is decreased when leukocytes are surrounded by a pro-inflammatory entourage. Our data strongly indicate that human leukocytes use AA and UFAs to biosynthesize biologically significant concentrations of 2-AG and other MAGs and that hijacking the immune system with 2-AG hydrolysis inhibitors might diminish inflammation in humans.

Human leukocytes differentially express endocannabinoid-glycerol lipases and hydrolyze 2-arachidonoyl-glycerol and its metabolites from the 15-lipoxygenase and cyclooxygenase pathways.

2-Arachidonoyl-glycerol (2-AG) is an endocannabinoid with anti-inflammatory properties. Blocking 2-AG hydrolysis to enhance CB2 signaling has proven effective in mouse models of inflammation. However, the expression of 2-AG lipases has never been thoroughly investigated in human leukocytes. Herein, we investigated the expression of seven 2-AG hydrolases by human blood leukocytes and alveolar macrophages (AMs) and found the following protein expression pattern: monoacylglycerol (MAG lipase; eosinophils, AMs, monocytes), carboxylesterase (CES1; monocytes, AMs), palmitoyl-protein thioesterase (PPT1; AMs), α/ß-hydrolase domain (ABHD6; mainly AMs), ABHD12 (all), ABHD16A (all), and LYPLA2 (lysophospholipase 2; monocytes, lymphocytes, AMs). We next found that all leukocytes could hydrolyze 2-AG and its metabolites derived from cyclooxygenase-2 (prostaglandin E2 -glycerol [PGE2 -G]) and the 15-lipoxygenase (15-hydroxy-eicosatetraenoyl-glycerol [15-HETE-G]). Neutrophils and eosinophils were consistently better at hydrolyzing 2-AG and its metabolites than monocytes and lymphocytes. Moreover, the efficacy of leukocytes to hydrolyze 2-AG and its metabolites was 2-AG  ≥ 15-HETE-G >> PGE2 -G for each leukocyte. Using the inhibitors methylarachidonoyl-fluorophosphonate (MAFP), 4-nitrophenyl-4-(dibenzo[d][1,3]dioxol-5-yl(hydroxy)methyl)piperidine-1-carboxylate (JZL184), Palmostatin B, 4'-carbamoylbiphenyl-4-yl methyl(3-(pyridin-4-yl)benzyl)carbamate, N-methyl-N-[[3-(4-pyridinyl)phenyl]methyl]-4'-(aminocarbonyl)[1,1'-biphenyl]-4-yl ester carbamic acid (WWL70), 4'-[[[methyl[[3-(4-pyridinyl)phenyl]methyl]amino]carbonyl]oxy]-[1,1'-biphenyl]-4-carboxylic acid, ethyl ester (WWL113), tetrahydrolipstatin, and ML349, we could not pinpoint a specific hydrolase responsible for the hydrolysis of 2-AG, PGE2 -G, and 15-HETE-G by these leukocytes. Furthermore, JZL184, a selective MAG lipase inhibitor, blocked the hydrolysis of 2-AG, PGE2 -G, and 15-HETE-G by neutrophils and the hydrolysis of PGE2 -G and 15-HETE-G by lymphocytes, two cell types with limited/no MAG lipase. Using an activity-based protein profiling (ABPP) probe to label hydrolases in leukocytes, we found that they express many MAFP-sensitive hydrolases and an unknown JZL184-sensitive hydrolase of ∼52 kDa. Altogether, our results indicate that human leukocytes are experts at hydrolyzing 2-AG and its metabolites via multiple lipases and probably via a yet-to-be characterized 52 kDa hydrolase. Blocking 2-AG hydrolysis in humans will likely abrogate the ability of human leukocytes to degrade 2-AG and its metabolites and increase their anti-inflammatory effects in vivo.

Effect of bronchial thermoplasty on structural changes and inflammatory mediators in the airways of subjects with severe asthma.

BACKGROUND: Bronchial thermoplasty (BT) is a novel technique used in the treatment of subjects with severe refractory asthma. Radiofrequency is provided to airway walls during bronchoscopy in order to reduce airway remodeling. Several clinical studies have reported an improvement in subjects' symptoms following BT. However, how BT affects the airway architectures and inflammatory mediators in the airways has not been yet fully elucidated. METHODS: Fourteen subjects with severe asthma were recruited in this study according to the criteria of ATS severe asthma definition. The study subjects undertook bronchial biopsy during the bronchoscopy procedure at baseline and 6 weeks after the initial BT treatment. The obtained samples were stained with antibodies for α-smooth muscle actin (α-SMA); protein gene product (PGP) 9.5, a specific nerve marker; von Willebrand factor (vWF), a marker for blood vessels; interleukin-17A (IL-17A) and transforming growth factor-ß1 (TGF-ß1). RESULTS: The expression of α-SMA and PGP9.5 were significantly reduced post-BT. There was no significant difference in the number of blood vessels between baseline and post-BT. In addition, BT did not affect the production of IL-17A and TGF-ß1 in the airways. The changes in the expression of α-SMA and PGP9.5 had no significant correlation with the improvement of pulmonary function. CONCLUSION: and Clinical Relevance: This study suggests that BT reduces airway smooth muscle mass and the airway innervation without affecting vasculature and the production of inflammatory mediators in the airways of subjects with severe asthma.

20-Hydroxy- and 20-carboxy-leukotriene (LT) B4 downregulate LTB4 -mediated responses of human neutrophils and eosinophils.

Leukotriene B4 (LTB4 ) plays a prominent role in innate immunity as it induces phagocyte recruitment, the release of antimicrobial effectors, and as it potentiates the ingestion and killing of pathogens. In humans, LTB4 has a short half-life and is rapidly metabolized by leukocytes, notably into 20-OH- and 20-COOH-LTB4 by neutrophils. Although these LTB4 metabolites bind to the BLT1 receptor with high affinity, they activate neutrophils to a much lower extent than LTB4 . We thus postulated that LTB4 metabolites could dampen BLT1 -mediated responses, therefore limiting the impact of LTB4 on human neutrophil functions. We found that 20-OH-LTB4 and 20-COOH-LTB4 inhibited all of the LTB4 -mediated neutrophil responses we tested (migration, degranulation, leukotriene biosynthesis). The potencies of the different compounds at inhibiting LTB4 -mediated responses were 20-OH-LTB4  = CP 105,696 (BLT1 antagonist) > > 20-COOH-LTB4 ≥ resolvin E1 (RVE1 ). In contrast, the fMLP- and IL-8-mediated responses we tested were not affected by the LTB4 metabolites or RVE1 . 20-OH-LTB4 and 20-COOH-LTB4 also inhibited the LTB4 -mediated migration of human eosinophils but not that induced by 5-KETE. Moreover, using 20-COOH-LTB4 , LTB4 , and LTB4 -alkyne, we show that LTB4 is a chemotactic, rather than a chemokinetic factor for both human neutrophils and eosinophils. In conclusion, our data indicate that LTB4 metabolites and RVE1 act as natural inhibitors of LTB4 -mediated responses. Thus, preventing LTB4 ω-oxidation might result in increased innate immunity and granulocyte functions.

Methylation profiles of IL33 and CCL26 in bronchial epithelial cells are associated with asthma.

AIM: This study aimed to characterize DNA methylation (DNA-me) in promoter region of IL33, IL1RL1 and CCL26 in asthma and their impacts on transcriptional activity in bronchial epithelial cells (BECs). PATIENTS & METHODS: We performed bis-pyrosequencing, quantitative real-time PCR and sequencing in BECs from ten asthmatic and ten control individuals. RESULTS: We detected lower DNA-me levels of IL33 and CCL26 in asthmatic than control BECs. No correlation was found between methylation and expression levels. Interestingly, carriers of a mutative allele in a haplotype within the promoter of IL33 had a lower IL33 DNA-me level and CCL26 gene expression correlated with eosinophil count. CONCLUSION: These findings highlight the importance of investigating both epigenetic and genetic mechanisms in understanding the epithelial immune response in asthma.

Tumor-based gene expression biomarkers to predict survival following curative intent resection for stage I lung adenocarcinoma.

BACKGROUND: Prognostic biomarkers are needed in clinical setting to predict outcome after resection for early-stage lung adenocarcinoma. The goal of this study is to validate tumor-based single-gene expression biomarkers with demonstrated prognostic value in order to move them along the clinical translation pipeline. METHODS: Prognostic genes were selected from the literature and the best candidates measured by quantitative real-time polymerase chain reaction (qPCR) in tumors of 233 patients with stage I adenocarcinoma. Significant prognostic genes were then validated in an independent set of 210 patients matching the first set in terms of histology, stage, and clinical data. RESULTS: Eleven genes with demonstrated prognostic value were selected from the literature. Complementary analyses in public databases and our own microarray dataset led to the investigation of six genes associated with good (BTG2, SELENBP1 and NFIB) or poor outcome (RRM1, EZH2 and FOXM1). In the first set of patients, EZH2 and RRM1 were significantly associated with better survival on top of age, sex and pathological stage (EZH2 p = 3.2e-02, RRM1 p = 5.9e-04). The prognostic values of EZH2 and RRM1 were not replicated in the second set of patients. A trend was observed for both genes in the joint analyses (n = 443) with higher expression associated with worse outcome. CONCLUSION: Adenocarcinoma-specific mRNA expression levels of EZH2 and RRM1 are associated with poor post-surgical survival in the first set of patients, but not replicated in a clinically and pathologically matched independent validation set. This study highlights challenges associated with clinical translation of prognostic biomarkers.