Background and Purpose IL‐11 is a member of the IL‐6 family of cytokine initially considered as haematopoietic and cytoprotective factor. Recent evidence indicates that IL‐11 promotes lung fibrosis and pulmonary hypertension in animal models and is elevated in lung tissue of patients with pulmonary fibrosis and pulmonary hypertension. Fibrocytes are bone marrow‐derived circulating cells that participate in lung fibrosis and pulmonary hypertension, but the role of IL‐11 on fibrocytes is unknown. We investigated the role of IL‐11 system on fibrocyte activation in different in vitro and in vivo models of lung fibrosis associated with pulmonary hypertension. Experimental Approach Human fibrocytes were isolated from peripheral blood of six healthy donors. Recombinant human (rh)‐IL‐11 and soluble rh‐IL‐11 receptor, α subunit (IL‐11Rα) were used to stimulated fibrocytes in vitro to measure:‐ cell migration in a chemotactic migration chamber, fibrocyte to endothelial cell adhesion in a microscope‐flow chamber and fibrocyte to myofibroblast transition. Mouse lung fibrosis and pulmonary hypertension was induced using either IL‐11 (s.c.) or bleomycin (intra‐tracheal), while in the rat monocrotaline (intra‐tracheal) was used. In vivo siRNA‐IL‐11 was administered to suppress IL‐11 in vivo . Key Results RhIL‐11 and soluble rhIL‐11Rα promote fibrocyte migration, endothelial cell adhesion and myofibroblast transition. Subcutaneous (s.c.) IL‐11 infusion elevates blood, bronchoalveolar and lung tissue fibrocytes. SiRNA‐IL‐11 transfection in bleomycin and monocrotaline animal models reduces blood and lung tissue fibrocytes and reduces serum CXCL12 and CXCL12/CXCR4 lung expression. Conclusion and Implications Targeting IL‐11 reduces fibrocyte circulation and lung accumulation in animal models of pulmonary hypertension‐associated lung fibrosis.

IL-11 is linked to fibrotic diseases, but its role in pulmonary hypertension is unclear. We examined IL-11's involvement in idiopathic pulmonary arterial hypertension (iPAH). Using samples from control (n = 20) and iPAH (n = 6) subjects, we assessed IL-11 and IL-11Rα expression and localization through RT-qPCR, ELISA, immunohistochemistry, and immunofluorescence. A monocrotaline-induced PAH model helped evaluate the impact of siRNA-IL-11 on pulmonary artery remodeling and PH. The effects of recombinant human IL-11 and IL-11Rα on human pulmonary artery smooth muscle cell (HPASMC) proliferation, pulmonary artery endothelial cell (HPAEC) mesenchymal transition, monocyte interactions, endothelial tube formation, and precision cut lung slice (PCLS) pulmonary artery remodeling and contraction were evaluated. IL-11 and IL-11Rα were over-expressed in pulmonary arteries (3.2-fold and 75-fold respectively) and serum (1.5-fold and 2-fold respectively) of patients with iPAH. Therapeutic transient transfection with siRNA targeting IL-11 resulted in a significant reduction in pulmonary artery remodeling (by 98%), right heart hypertrophy (by 66%), and pulmonary hypertension (by 58%) in rats exposed to monocrotaline treatment. rhIL-11 and soluble rhIL-11Rα induce HPASMC proliferation and HPAEC to monocyte interactions, mesenchymal transition, and tube formation. Neutralizing monoclonal IL-11 and IL-11Rα antibodies inhibited TGFβ1 and EDN-1 induced HPAEC to mesenchymal transition and HPASMC proliferation. In 3D PCLS, rhIL-11 and soluble rhIL-11Rα do not promote pulmonary artery contraction but sensitize PCLS pulmonary artery contraction induced by EDN-1.In summary, IL-11 and IL-11Rα are more highly expressed in the pulmonary arteries of iPAH patients and contribute to pulmonary artery remodeling and the development of PH.

Abstract Background Pulmonary hypertension (PH) associated to idiopathic pulmonary fibrosis (IPF) portends a poor prognosis. IL-11 has been implicated in fibrotic diseases, but their role on pulmonary vessels is unknown. Here we analyzed the contribution of IL-11 to PH in patients with IPF and the potential mechanism implicated. Methods Pulmonary arteries, lung tissue and serum of control subjects (n = 20), IPF (n = 20) and PH associated to IPF (n = 20) were used to study the expression and localization of IL-11 and IL-11Rα. Two models of IL-11 and bleomycin-induced lung fibrosis associated to PH were used in Tie2-GFP transgenic mice to evaluate the contribution of IL-11 and endothelial cells to pulmonary artery remodeling. The effect of IL-11 and soluble IL-11Rα on human pulmonary artery endothelial cells and smooth muscle cell transformations and proliferation were analyzed. Results IL-11 and IL-11Rα were over-expressed in pulmonary arteries and serum of patients with PH associated to IPF vs IPF patients without PH. Recombinant mice (rm)IL-11 induced lung fibrosis and PH in Tie2-GFP mice, activating in vivo EnMT as a contributor of pulmonary artery remodeling and lung fibrosis. Transient transfection of siRNA-IL-11 reduced lung fibrosis and PH in Tie2-GFP bleomycin model. Human (h)rIL-11 and soluble hrIL-11Rα induced endothelial to mesenchymal transition (EnMT) and pulmonary artery smooth muscle cell to myofibroblast-like transformation, cell proliferation and senescence in vitro. Conclusions IL-11 and IL-11Rα are overexpressed in pulmonary arteries of PH associated to IPF patients, and contributes to pulmonary artery remodeling and PH.

Several mucins are implicated in idiopathic pulmonary fibrosis (IPF); however, there is no evidence regarding the role of MUC4 in the development of IPF. Here we demonstrated that MUC4 was overexpressed in IPF patients (n = 22) compared with healthy subjects (n = 21) and located in pulmonary arteries, bronchial epithelial cells, fibroblasts, and hyperplastic alveolar type II cells. Decreased expression of MUC4 using siRNA–MUC4 inhibited the mesenchymal/myofibroblast transformations of alveolar type II A549 cells and lung fibroblasts, as well as cell senescence and fibroblast proliferation induced by TGF-β1. The induction of the overexpression of MUC4 increased the effects of TGF-β1 on mesenchymal/myofibroblast transformations and cell senescence. MUC4 overexpression and siRNA–MUC4 gene silencing increased or decreased, respectively, the phosphorylation of TGFβRI and SMAD3, contributing to smad-binding element activation. Immunoprecipitation analysis and confocal immunofluorescence showed the formation of a protein complex between MUC4β/p-TGFβRI and p-SMAD3 in the cell membrane after TGF-β1 stimulation and in lung tissue from IPF patients. Bleomycin-induced lung fibrosis was reduced in mice transiently transfected with siRNA–MUC4. This study shows that MUC4 expression is enhanced in IPF and promotes fibrotic processes in collaboration with TGF-β1 canonical pathway that could be an attractive druggable target for human IPF.

BACKGROUND:Serum KL6/mucin 1 (MUC1) has been identified as a potential biomarker in idiopathic pulmonary fibrosis (IPF), but the role of MUC1 intracellular bioactivation in IPF is unknown.OBJECTIVE:To characterise MUC1 intracellular bioactivation in IPF.METHODS AND RESULTS:The expression and phosphorylation of Thr41 and Tyr46 on the intracellular MUC1-cytoplasmic tail (CT) was increased in patients with IPF (n=22) compared with healthy subjects (n=21) and localised to fibroblasts and hyperplastic alveolar type II cells. Transforming growth factor (TGF)-β1 phosphorylated SMAD3 and thereby increased the phosphorylation of MUC1-CT Thr41 and Tyr46 in lung fibroblasts and alveolar type II cells, activating β-catenin to form a phospho-Smad3/MUC1-CT and MUC1-CT/β-catenin nuclear complex. This nuclear complex promoted alveolar epithelial type II and fibroblast to myofibroblast transitions, as well as cell senescence and fibroblast proliferation. The inhibition of MUC1-CT nuclear translocation using the inhibitor, GO-201 or silencing MUC1 by siRNA, reduced myofibroblast transition, senescence and proliferation in vitro. Bleomycin-induced lung fibrosis was reduced in mice treated with GO-201 and in MUC1-knockout mice. The profibrotic lectin, galectin-3, directly activated MUC1-CT and served as a bridge between the TGF-β receptor and the MUC1-C domain, indicating TGF-β1-dependent and TGF-β1-independent intracellular bioactivation of MUC1.CONCLUSIONS:MUC1 intracellular bioactivation is enhanced in IPF and promotes fibrotic processes that could represent potential druggable targets for IPF.

Background Pulmonary hypertension (PH) is a common disorder in patients with idiopathic pulmonary fibrosis (IPF) and portends a poor prognosis. Recent studies using vasodilators approved for PH have failed in improving IPF mainly due to ventilation (V)/perfusion (Q) mismatching and oxygen desaturation. Janus kinase type 2 (JAK2) is a non-receptor tyrosine kinase activated by a broad spectrum of profibrotic and vasoactive mediators, but its role in PH associated to PH is unknown. Objective The study of JAK2 as potential target to treat PH in IPF. Methods and results JAK2 expression was increased in pulmonary arteries (PAs) from IPF (n=10; 1.93-fold; P=0.0011) and IPF+PH (n=9; 2.65-fold; P<0.0001) compared with PA from control subjects (n=10). PA remodelling was evaluated in human pulmonary artery endothelial cells (HPAECs) and human pulmonary artery smooth muscle cells (HPASMCs) from patients with IPF in vitro treated with the JAK2 inhibitor JSI-124 or siRNA-JAK2 and stimulated with transforming growth factor beta. Both JSI-124 and siRNA-JAK2 inhibited the HPAEC to mesenchymal transition and the HPASMCs to myofibroblast transition and proliferation. JAK2 inhibition induced small PA relaxation in precision-cut lung slice experiments. PA relaxation was dependent of the large conductance calcium-activated potassium channel (BKCa). JAK2 inhibition activated BKCa channels and reduced intracellular Ca2+. JSI-124 1 mg/kg/day, reduced bleomycin-induced lung fibrosis, PA remodelling, right ventricular hypertrophy, PA hypertension and V/Q mismatching in rats. The animal studies followed the ARRIVE guidelines. Conclusions JAK2 participates in PA remodelling and tension and may be an attractive target to treat IPF associated to PH.

BACKGROUND:The loss of corticosteroid efficacy is an important issue in severe asthma management and may lead to poor asthma control and deterioration of airflow. Recent data indicate that Mucin 1 (MUC1) membrane mucin can mediate corticosteroid efficacy in chronic rhinosinusitis, but the role of MUC1 in uncontrolled severe asthma is unknown. The objective was to analyze the previously unexplored role of MUC1 on corticosteroid efficacy in asthma.METHODS:Mucin 1 expression was evaluated by real-time PCR in human bronchial epithelial cells (HBEC) and blood neutrophils from uncontrolled severe asthma (n = 27), controlled mild asthma (n = 16), and healthy subjects (n = 13). IL-8, MMP9, and GM-CSF were measured by ELISA in HBEC and neutrophils. An asthma model of ovalbumin (OVA) was used in MUC1 KO and WT C57BL/6 mice according to ARRIVE guidelines.RESULTS:Mucin 1-CT expression was downregulated in bronchial epithelial cells and peripheral blood neutrophils from severe asthma patients compared with mild asthma and healthy subjects (P < 0.05). Daily dose of inhaled corticosteroids (ICS) inversely correlated with MUC1 expression in neutrophils from mild and severe asthma (ρ = -0.71; P < 0.0001). Dexamethasone showed lower anti-inflammatory effects in severe asthma peripheral blood neutrophils and HBECs stimulated with lipopolysaccharide (LPS) than in cells from mild asthma. Glucocorticoid receptor (GR)-α phosphorylated at serine 226 was increased in cells from severe asthma, and the MUC1-CT/GRα complex was downregulated in severe asthma cells. OVA asthma model in MUC1 KO mice was resistant to the anti-inflammatory effects of dexamethasone.CONCLUSION:Mucin 1-CT modulates corticosteroid efficacy in vitro and in vivo asthma models.

Sildenafil improves the 6-min walking distance in patients with idiopathic pulmonary fibrosis (IPF) and right-sided ventricular systolic dysfunction. We analysed the previously unexplored role of sildenafil on vasoconstriction and remodelling of pulmonary arteries from patients with IPF and pulmonary hypertension (PH) ex vivo . Pulmonary arteries from 18 donors without lung disease, nine IPF, eight PH+IPF and four PH patients were isolated to measure vasodilator and anti-contractile effects of sildenafil in isometric organ bath. Ventilation/perfusion was explored in an animal model of bleomycin lung fibrosis. Sildenafil relaxed serotonin (5-HT) pre-contracted pulmonary arteries in healthy donors and IPF patients and, to a lesser extent, in PH+IPF and PH. Sildenafil inhibited 5-HT dose-response contraction curve mainly in PH+IPF and PH, but not in healthy donors. Sildenafil did not impair the ventilation/perfusion mismatching induced by bleomycin. Pulmonary arteries from PH+IPF patients showed a marked expression of phosphodiesterse-5 and extracellular matrix components. Sildenafil inhibited pulmonary artery endothelial and smooth muscle cell to mesenchymal transition by inhibition of extracellular regulated kinases 1 and 2 (ERK1/2) and SMAD3 phosphorylation. These results suggest an absence of direct relaxant effect and a prominent anti-contractile and anti-remodelling role of sildenafil in PH+IPF pulmonary arteries that could explain the beneficial effects of sildenafil in IPF with PH phenotype.

Cigarette smoking contributes to lung remodelling in chronic obstructive pulmonary disease (COPD). As part of this remodelling, peribronchiolar fibrosis is observed in the small airways of COPD patients and contributes to airway obstruction. Fibroblast-to-myofibroblast transition is a key step in peribronchiolar fibrosis formation. This in vitro study examined the effect of cigarette smoke on bronchial fibroblast-to-myofibroblast transition, and whether aclidinium bromide inhibits this process. Human bronchial fibroblasts were incubated with aclidinium bromide (10−9–10−7 M) and exposed to cigarette smoke extract. Collagen type I and α-smooth muscle actin (α-SMA) expression were measured by real-time PCR and Western blotting, as myofibroblast markers. Intracellular reactive oxygen species, cyclic AMP (cAMP), extracellular signal-regulated kinase (ERK)1/2 and choline acetyltransferase were measured as intracellular signalling mediators. Cigarette smoke-induced collagen type I and α-SMA was mediated by the production of reactive oxygen species, the depletion of intracellular cAMP and the increase of ERK1/2 phosphorylation and choline acetyltransferase. These effects could be reversed by treatment with the anticholinergic aclidinium bromide, by silencing the mRNA of muscarinic receptors M1, M2 or M3, or by the depletion of extracellular acetylcholine by treatment with acetylcholinesterase. A non-neuronal cholinergic system is implicated in cigarette smoke-induced bronchial fibroblast-to-myofibroblast transition, which is inhibited by aclidinium bromide.

BACKGROUND AND PURPOSE Mucociliary malfunction occurs in chronic obstructive pulmonary disease (COPD) and compromised functions of ciliated bronchial epithelial cells may contribute to this. Cigarette smoke, a major risk factor for COPD, impairs ciliary beat frequency (CBF). cAMP augments CBF. This in vitro study addressed, in differentiated, primary human bronchial epithelial cells, whether roflumilast N‐oxide, a PDE4 inhibitor, (i) augments CBF; (ii) prevents the reduction in CBF induced by cigarette smoke extract (CSE); and (iii) protects against the loss of the ciliated phenotype following long‐term CSE exposure.

La situación clínica, morfológica y funcional del páncreas tras el episodio de pancreatitis retorna a la normalidad si se elimina la causa primaria y las complicaciones. El objetivo del estudio es valorar si existen cambios en la morfología del conducto pancreático después de la pancreatitis aguda de origen biliar. Se estudia prospectivamente a 40 pacientes consecutivos con pancreatitis aguda biliar, 15 varones (37,5%) y 25 mujeres (62,5%), 27 leves y 13 graves. Durante la fase aguda se evaluó la gravedad siguiendo los criterios de Atlanta, así como la existencia de necrosis y su porcentaje mediante tomografía computarizada dinámica. A todos los pacientes se les practicó colecistectomía. Durante el seguimiento valoramos la morfología de la glándula y el conducto pancreático principal mediante colangiopancreatografía por resonancia magnética, realizando el mismo estudio con un grupo control. Analizamos si tras la pancreatitis aguda de origen biliar existe alteración de la morfología de la glándula y del conducto pancreático, y si estas alteraciones se relacionan con la gravedad del episodio, valorando su progresión hacia la cronicidad. Se aprecian algunas diferencias significativas al comparar el diámetro y la longitud del conducto pancreático principal de los casos y los controles. No se encontró ninguna relación entre la gravedad de la enfermedad y las alteraciones morfológicas del páncreas tras la pancreatitis. Tras la pancreatitis aguda se detectan alteraciones morfológicas pancreáticas consideradas como secuelas cicatrizales, sin traducción hacia la cronicidad y sin relación con la gravedad. The clinical, morphological and functional features of the pancreas return to normal after an episode of pancreatitis if the primary cause of the episode and its complications are eliminated. The aim of this study was to evaluate whether the morphology of the pancreatic duct changes after acute biliary pancreatitis. We prospectively studied 40 consecutive patients with acute biliary pancreatitis. There were 15 men (37.5%) and 25 women (62.5%). Pancreatitis was mild in 27 patients and severe in 13. In the acute phase, severity was evaluated using the Atlanta criteria. The existence of necrosis and its percentage were evaluated through dynamic computed tomography. All patients underwent cholecystectomy. During follow-up, morphology of the pancreas and of the main pancreatic duct were evaluated through magnetic resonance cholangiopancreatography. A control group also underwent this procedure. We analyzed whether alterations occurred in the morphology of the pancreas and of the pancreatic duct after acute biliary pancreatitis and whether these alterations are related with the severity of the episode by evaluating their progression towards chronicity. Comparison of the diameter and length of the main pancreatic duct revealed some significant differences between cases and controls. No relationship was found between severity of the disease and morphologic alterations of the pancreas after pancreatitis. After acute pancreatitis, morphologic alterations considered as scarring were detected. No relationship was found between these alterations and chronicity or severity.

Following the Cambridge and Marseilles Symposia, functional recovery of the pancreas occurs if the primary cause and complications of the disease have been eliminated. However, recent research showed contradictory results, owing to the difference in diagnostic methods and the proportion of patients studied in relation to the etiologic factor and severity of the disease, as well as the differences in the tests utilized. Sixty-three consecutive patients with acute biliary pancreatitis were prospectively studied. Seventeen were men (27%) and 46 were women (73%), with an average age of 62.3 years, 45 were mild cases and 18 were severe. All patients underwent a cholecystectomy. No patient in this series underwent necrosectomy. During the acute phase, severity was evaluated following the Atlanta criteria as well as the existence of necrosis and its percentage by means of dynamic computed tomography (CT). During the follow-up, different tests were used to assess the pancreatic exocrine function, 1 month, 6 months and 1 year after the acute pancreatitis (AP) episode. The possible existence of pancreatic exocrine insufficiency following biliary origin AP as well as whether this possible deficit was relat- ed to the severity of the episode was investigated. We found no such insufficiency 1 year after the episode, and no link with the severity of the episode.