ResearchPad - trachea https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[Odiparcil, a potential glycosaminoglycans clearance therapy in mucopolysaccharidosis VI—Evidence from <i>in vitro</i> and <i>in vivo</i> models]]> https://www.researchpad.co/article/elastic_article_14726 Mucopolysaccharidoses are a class of lysosomal storage diseases, characterized by enzymatic deficiency in the degradation of specific glycosaminoglycans (GAG). Pathological accumulation of excess GAG leads to multiple clinical symptoms with systemic character, most severely affecting bones, muscles and connective tissues. Current therapies include periodic intravenous infusion of supplementary recombinant enzyme (Enzyme Replacement Therapy–ERT) or bone marrow transplantation. However, ERT has limited efficacy due to poor penetration in some organs and tissues. Here, we investigated the potential of the β-D-xyloside derivative odiparcil as an oral GAG clearance therapy for Maroteaux–Lamy syndrome (Mucopolysaccharidosis type VI, MPS VI). In vitro, in bovine aortic endothelial cells, odiparcil stimulated the secretion of sulphated GAG into culture media, mainly of chondroitin sulphate (CS) /dermatan sulphate (DS) type. Efficacy of odiparcil in reducing intracellular GAG content was investigated in skin fibroblasts from MPS VI patients where odiparcil was shown to reduce efficiently the accumulation of intracellular CS with an EC50 in the range of 1 μM. In vivo, in wild type rats, after oral administrations, odiparcil was well distributed, achieving μM concentrations in MPS VI disease-relevant tissues and organs (bone, cartilage, heart and cornea). In MPS VI Arylsulphatase B deficient mice (Arsb-), after chronic oral administration, odiparcil consistently stimulated the urinary excretion of sulphated GAG throughout the treatment period and significantly reduced tissue GAG accumulation in liver and kidney. Furthermore, odiparcil diminished the pathological cartilage thickening observed in trachea and femoral growth plates of MPS VI mice. The therapeutic efficacy of odiparcil was similar in models of early (treatment starting in juvenile, 4 weeks old mice) or established disease (treatment starting in adult, 3 months old mice). Our data demonstrate that odiparcil effectively diverts the synthesis of cellular glycosaminoglycans into secreted soluble species and this effect can be used for reducing cellular and tissue GAG accumulation in MPS VI models. Therefore, our data reveal the potential of odiparcil as an oral GAG clearance therapy for MPS VI patients.

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<![CDATA[Augmentation of curved tip of left-sided double-lumen tubes to reduce right bronchial misplacement: A randomized controlled trial]]> https://www.researchpad.co/article/5c478c5bd5eed0c484bd1d52

Background

During intubation with a blind technique, a left-sided double-lumen tube (DLT) can be misdirected into the right bronchus even though its curved tip of the bronchial lumen turns to the left. This right bronchial misplacement may be associated with the tip angle of DLTs. We thus performed a randomized trial to test the hypothesis that the DLT with an acute tip angle enters the right bronchus less frequently than the tube with an obtuse tip angle.

Methods

We randomized surgical patients (n = 1427) receiving a polyvinyl chloride left-sided DLT. Before intubation, the curved tip was further bent to an angle of 135° and kept with a stylet inside in the curved-tip group, but not in the control group. After the tip was inserted into the glottis under direct or video laryngoscopy, the stylet was removed and the DLT was advanced into the bronchus with its tip turning to the left. We checked which bronchus was intubated, and the time and number of attempts for intubation. After surgery, we assessed airway injury, sore throat, and hoarseness. The primary outcome was the incidence of right bronchial misplacement of the DLT.

Results

DLTs were misdirected into the right bronchus more frequently in the control group than in the curved-tip group: 57/715 (8.0%) vs 17/712 (2.4%), risk ratio (95% CI) 3.3 (2.0–5.7), P < 0.001. The difference was significant in the use of 32 (P = 0.003), 35 (P = 0.007), and 37 (P = 0.012) Fr DLTs. Intubation required longer time (P < 0.001) and more attempts (P = 0.002) in the control group. No differences were found in postoperative airway injury, sore throat and hoarseness.

Conclusions

Before intubation of left-sided DLTs, augmentation of the curved DLT tip reduced the right bronchial misplacement and facilitated intubation without aggravating airway injury.

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<![CDATA[Trynity controls epidermal barrier function and respiratory tube maturation in Drosophila by modulating apical extracellular matrix nano-patterning]]> https://www.researchpad.co/article/5c269730d5eed0c48470edff

The outer surface of insects is covered by the cuticle, which is derived from the apical extracellular matrix (aECM). The aECM is secreted by epidermal cells during embryogenesis. The aECM exhibits large variations in structure, function, and constituent molecules, reflecting the enormous diversity in insect appearances. To investigate the molecular principles of aECM organization and function, here we studied the role of a conserved aECM protein, the ZP domain protein Trynity, in Drosophila melanogaster. We first identified trynity as an essential gene for epidermal barrier function. trynity mutation caused disintegration of the outermost envelope layer of the cuticle, resulting in small-molecule leakage and in growth and molting defects. In addition, the tracheal tubules of trynity mutants showed defects in pore-like structures of the cuticle, and the mutant tracheal cells failed to absorb luminal proteins and liquid. Our findings indicated that trynity plays essential roles in organizing nano-level structures in the envelope layer of the cuticle that both restrict molecular trafficking through the epidermis and promote the massive absorption pulse in the trachea.

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<![CDATA[Usefulness of C-MAC video laryngoscope in direct laryngoscopy training in the emergency department: A propensity score matching analysis]]> https://www.researchpad.co/article/5c1ab86dd5eed0c48402800d

Objectives

We determined the usefulness of C-MAC video laryngoscope (C-MAC) as a safe training tool for the direct laryngoscopy technique in the emergency department.

Methods

We retrospectively analyzed an institutional airway registry of adult (≥18 years old) patients from April 2014 through October 2016. In this study, the operator used C-MAC as a direct laryngoscope (DL) with limited access to the screen, and the supervisor instructed the operator via verbal feedback while watching the screen. Patients were categorized into the DL group if a conventional DL was used and the C-DL group if a C-MAC used as a DL.

Results

Of 744 endotracheal intubations, 163 propensity score-matched pairs were generated (1-to-n matching: C-DL group, 163 vs. DL group, 428). For the propensity-matched groups, the overall first pass success rate was 69%, while those in the C-DL and DL groups were 79% and 65%, respectively. Overall, multiple attempts were required in 8% of patients, with 4% in the C-DL group and 9% in the DL group. The overall complication rate was 11%, with 4% in the C-DL group and 14% in the DL group. In multivariable analysis, the adjusted odds ratios of C-DL use for first pass success, multiple attempts, and complications were 2.05 (95% confidence interval [CI] 1.18–2.87, p < 0.01), 0.38 (95% CI 0.15–0.94; p < 0.01), and 0.28 (95% CI 0.12–0.63; p < 0.01), respectively.

Conclusions

Our study suggests that the C-MAC could be useful for training residents in the direct laryngoscopy while ensuring patient safety in the emergency department.

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<![CDATA[Anisotropic Crb accumulation, modulated by Src42A, is coupled to polarised epithelial tube growth in Drosophila]]> https://www.researchpad.co/article/5c059de3d5eed0c4849c965b

The control of the size of internal tubular organs, such as the lungs or vascular system, is critical for proper physiological activity and to prevent disease or malformations. This control incorporates the intrinsic physical anisotropy of tubes to generate proportionate organs that match their function. The exact mechanisms underlying tube size control and how tubular anisotropy is translated at the cellular level are still not fully understood. Here we investigate these mechanisms using the Drosophila tracheal system. We show that the apical polarity protein Crumbs transiently accumulates anisotropically at longitudinal cell junctions during tube elongation. We provide evidence indicating that the accumulation of Crumbs in specific apical domains correlates with apical surface expansion, suggesting a link between the anisotropic accumulation of Crumbs at the cellular level and membrane expansion. We find that Src42A is required for the anisotropic accumulation of Crumbs, thereby identifying the first polarised cell behaviour downstream of Src42A. Our results indicate that Src42A regulates a mechanism that increases the fraction of Crb protein at longitudinal junctions, and genetic interaction experiments are consistent with Crb acting downstream of Src42A in controlling tube size. Collectively, our results suggest a model in which Src42A would sense the inherent anisotropic mechanical tension of the tube and translate it into a polarised Crumbs accumulation, which may promote a bias towards longitudinal membrane expansion, orienting cell elongation and, as a consequence, longitudinal growth at the tissue level. This work provides new insights into the key question of how organ growth is controlled and polarised and unveils the function of two conserved proteins, Crumbs and Src42A, with important roles in development and homeostasis as well as in disease, in this biological process.

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<![CDATA[Determination of the minimum protective dose of a glycoprotein-G-deficient infectious laryngotracheitis virus vaccine delivered via eye-drop to week-old chickens]]> https://www.researchpad.co/article/5c12cf12d5eed0c484913e55

Infectious laryngotracheitis (ILT) is an upper respiratory tract disease of chickens that is caused by infectious laryngotracheitis virus (ILTV), an alphaherpesvirus. This disease causes significant economic loses in poultry industries worldwide. Despite widespread use of commercial live attenuated vaccines, many poultry industries continue to experience outbreaks of disease caused by ILTV. Efforts to improve the control of this disease have resulted in the generation of new vaccine candidates, including ILTV mutants deficient in virulence factors. A glycoprotein G deletion mutant vaccine strain of ILTV (ΔgG ILTV), recently licenced as Vaxsafe ILT (Bioproperties Pty Ltd), has been extensively characterised in vitro and in vivo, but the minimum effective dose required to protect inoculated animals has not been determined. This study performed a vaccination and challenge experiment to determine the minimum dose of ΔgG ILTV that, when delivered by eye-drop to seven-day-old specific pathogen-free chickens, would protect the birds from a robust challenge with a virulent field strain of virus (class 9 ILTV). A dose of 103.8 plaque forming units was the lowest dose capable of providing a high level of protection against challenge, as measured by clinical signs of disease, tracheal pathology and virus replication after challenge. This study has shown that the ΔgG ILTV vaccine strain is capable of inducing a high level of protection against a virulent field virus at a commercially feasible dose. These results lay the foundations upon which a commercial vaccine can be developed, thereby offering the potential to provide producers with another important tool to help control ILTV.

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<![CDATA[Inhibition of a NF-κB/Diap1 Pathway by PGRP-LF Is Required for Proper Apoptosis during Drosophila Development]]> https://www.researchpad.co/article/5989db54ab0ee8fa60bdd114

NF-κB pathways are key signaling cascades of the Drosophila innate immune response. One of them, the Immune Deficiency (IMD) pathway, is under a very tight negative control. Although molecular brakes exist at each step of this signaling module from ligand availability to transcriptional regulation, it remains unknown whether repressors act in the same cells or tissues and if not, what is rationale behind this spatial specificity. We show here that the negative regulator of IMD pathway PGRP-LF is epressed in ectodermal derivatives. We provide evidence that, in the absence of any immune elicitor, PGRP-LF loss-of-function mutants, display a constitutive NF-κB/IMD activation specifically in ectodermal tissues leading to genitalia and tergite malformations. In agreement with previous data showing that proper development of these structures requires induction of apoptosis, we show that ectopic activation of NF-κB/IMD signaling leads to apoptosis inhibition in both genitalia and tergite primordia. We demonstrate that NF-κB/IMD signaling antagonizes apoptosis by up-regulating expression of the anti-apoptotic protein Diap1. Altogether these results show that, in the complete absence of infection, the negative regulation of NF-κB/IMD pathway by PGRP-LF is crucial to ensure proper induction of apoptosis and consequently normal fly development. These results highlight that IMD pathway regulation is controlled independently in different tissues, probably reflecting the different roles of this signaling cascade in both developmental and immune processes.

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<![CDATA[Avertin®, but Not Volatile Anesthetics Addressing the Two-Pore Domain K+ Channel, TASK-1, Slows Down Cilia-Driven Particle Transport in the Mouse Trachea]]> https://www.researchpad.co/article/5989da0fab0ee8fa60b78ee7

Rationale

Volatile anesthetics inhibit mucociliary clearance in the airways. The two-pore domain K+ channel, TASK-1, represents one of their molecular targets in that they increase its open probability. Here, we determine whether particle transport speed (PTS) at the mucosal surface of the mouse trachea, an important factor of the cilia-driven mechanism in mucociliary clearance, is regulated by TASK-1.

Methodology/Results

RT-PCR analysis revealed expression of TASK-1 mRNA in the manually dissected and laser-assisted microdissected tracheal epithelium of the mouse. Effects of anesthetics (isoflurane and Avertin®) and TASK-1 inhibitors (anandamide and A293) on ciliary activity were investigated by assessment of PTS at the mucosal surface of the explanted and opened murine trachea. Neither TASK-1 inhibitors nor isoflurane had any impact on basal and ATP-stimulated PTS. Avertin® reduced basal PTS, and ATP-stimulated PTS decreased in its presence in wild-type (WT) mice. Avertin®-induced decrease in basal PTS persisted in WT mice in the presence of TASK-1 inhibitors, and in two different strains of TASK-1 knockout mice.

Conclusions/Significance

Our findings indicate that TASK-1 is expressed by the tracheal epithelium but is not critically involved in the regulation of tracheal PTS in mice. Avertin® reduces PTS independent of TASK-1.

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<![CDATA[XB130 Deficiency Affects Tracheal Epithelial Differentiation during Airway Repair]]> https://www.researchpad.co/article/5989dacaab0ee8fa60bb3f2c

The repair and regeneration of airway epithelium is important for maintaining homeostasis of the respiratory system. XB130 is an adaptor protein involved in the regulation of cell proliferation, survival and migration. In the human trachea, XB130 is expressed on the apical site of ciliated epithelial cells. We hypothesize that XB130 may play a role in epithelial repair and regeneration after injury. Xb130 knockout (KO) mice were generated, and a mouse isogenic tracheal transplantation model was used. Adult Xb130 KO mice did not show any significant anatomical and physiological phenotypes in comparison with their wild type (WT) littermates. The tracheal epithelium in Xb130 KO mice, however, was significantly thicker than that in WT mice. Severe ischemic epithelial injury was observed immediately after the tracheal transplantation, which was followed by epithelial cell flattening, proliferation and differentiation. No significant differences were observed in terms of initial airway injury and apoptosis. However, at Day 10 after transplantation, the epithelial layer was significantly thicker in Xb130 KO mice, and associated with greater proliferative (Ki67+) and basal (CK5+) cells, as well as thickening of the connective tissue and fibroblast layer between the epithelium and tracheal cartilages. These results suggest that XB130 is involved in the regulation of airway epithelial differentiation, especially during airway repair after injury.

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<![CDATA[Genetically diverse herpesviruses in South American Atlantic coast seabirds]]> https://www.researchpad.co/article/5989db5cab0ee8fa60be0291

Different herpesviruses have been associated with respiratory and enteric disease and mortality among seabirds and waterfowl. In 2011, a respiratory disease outbreak affected 58.3% (98/168) of the Magellanic penguins undergoing rehabilitation due to an oil spill off the southern Brazilian coast. Etiology was attributed to a novel herpesvirus identified by histopathology, immunohistochemistry, electron microscopy and molecular studies with partial DNA sequencing. Since migration, rehabilitation and translocation may facilitate the spread of pathogens between populations and trigger the onset of clinical disease in animals with latent infections, investigation of herpesvirus occurrence in asymptomatic seabirds was performed. Samples from free-ranging seabirds were collected in Argentinian Patagonia (Magellanic penguins) and the Abrolhos Archipelago in Brazil (Brown boobies, Masked boobies, Red-billed tropicbirds, White-tailed tropicbirds and South American tern). Furthermore, asymptomatic seabirds housed at the facility where the outbreak occurred were also sampled. In total, 354 samples from eight seabird species were analyzed by PCR for herpesvirus. Four different sequences of herpesviruses were identified, one in Yellow-nosed Albatross, one in Boobies and Tropicbirds and two in Magellanic penguins. Magellanic penguin herpesvirus 1 was identified during the penguin outbreak at the rehabilitation facility in Brazil, while Magellanic penguin herpesvirus 2 was recovered from free-ranging penguins at four reproduction sites in Argentina. Phylogenic analysis of the herpesviruses sequences tentatively identified suggested that the one found in Suliformes and the one associated with the outbreak are related to sequences of viruses that have previously caused seabird die-offs. These findings reinforce the necessity for seabird disease surveillance programs overall, and particularly highlight the importance of quarantine, good hygiene, stress management and pre-release health exams in seabirds undergoing rehabilitation.

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<![CDATA[On the Morphological Description of Tracheal and Esophageal Displacement and Its Phylogenetic Distribution in Avialae]]> https://www.researchpad.co/article/5989da6dab0ee8fa60b93a8f

This research examines the evolution and phylogenetic distribution of a peculiar and often overlooked character seen in birds, herein called tracheal and esophageal displacement. Tracheal and esophageal displacement refers to an asymmetrically situated trachea and/or esophagus along the length of the neck. This contrasts with what would be perceived as the “normal” (midsagittal) placement of these organs, wherein the two organs are situated along the ventral midline of the neck with no deviation. A total of forty-two bird species were examined (thirty-six of which came from dissections whereas six came from comments from previous literature or personal observations), as well as turtles, lizards, crocodylians, and mammals. This study found that essentially all birds have a laterally displaced trachea and/or esophagus. Lizards and mammals were seen to have normal, midsagittally placed tracheae and esophagi. Crocodylians were interesting in that alligators were defined by a normally situated trachea and esophagus whereas some crocodiles were characterized by displacement. In birds, the displacement may occur gradually along the neck, or it may happen immediately upon exiting the oropharynx. Displacement of these organs in birds is the result of a heavily modified neck wherein muscles that restrict mobility of the trachea and esophagus in lizards, alligators, and mammals (e.g., m. episternocleidomastoideus, m. omohyoideus, and m. sternohyoideus) no longer substantially restrict positions of the trachea and esophagus in birds. Rather, these muscles are modified in ways which may assist with making tracheal movements. The implications of this study may provide interesting insights for future comparisons in extinct taxa.

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<![CDATA[Parainfluenza 3-Induced Cough Hypersensitivity in the Guinea Pig Airways]]> https://www.researchpad.co/article/5989da69ab0ee8fa60b926a9

The effect of respiratory tract viral infection on evoked cough in guinea pigs was evaluated. Guinea pigs were inoculated intranasally with either parainfluenza type 3 (PIV3) and cough was quantified in conscious animals. The guinea pigs infected with PIV3 (day 4) coughed nearly three times more than those treated with the viral growth medium in response to capsaicin, citric acid, and bradykinin. Since capsaicin, citric acid, and bradykinin evoked coughing in guinea pigs can be inhibited by drugs that antagonize the transient receptor potential cation channel, subfamily V, member 1 (TRPV1), it was reasoned that the virally-induced hypertussive state may involve alterations in TPRV1 activity. PIV3 infection caused a phenotypic switch in tracheal nodose Aδ “cough receptors” such that nearly 50% of neurons began to express, de novo, TRPV1 mRNA. There was also an increase TRPV1 expression in jugular C-fiber neurons as determined by qPCR. It has previously been reported that tracheal-specific nodose neurons express the BDNF receptor TrkB and jugular neurons express the NGF receptor TrkA. Jugular neurons also express the artemin receptor GFRα3. All these neurotrophic factors have been associated with increases in TRPV1 expression. In an ex vivo perfused guinea pig tracheal preparation, we demonstrated that within 8 h of PIV3 infusion there was no change in NGF mRNA expression, but there was nearly a 10-fold increase in BDNF mRNA in the tissue, and a small but significant elevation in the expression of artemin mRNA. In summary, PIV3 infection leads to elevations in TRPV1 expression in the two key cough evoking nerve subtypes in the guinea pig trachea, and this is associated with a hypertussive state with respect to various TRPV1 activating stimuli.

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<![CDATA[Mutation of Growth Arrest Specific 8 Reveals a Role in Motile Cilia Function and Human Disease]]> https://www.researchpad.co/article/5989db4bab0ee8fa60bda1db

Ciliopathies are genetic disorders arising from dysfunction of microtubule-based cellular appendages called cilia. Different cilia types possess distinct stereotypic microtubule doublet arrangements with non-motile or ‘primary’ cilia having a 9+0 and motile cilia have a 9+2 array of microtubule doublets. Primary cilia are critical sensory and signaling centers needed for normal mammalian development. Defects in their structure/function result in a spectrum of clinical and developmental pathologies including abnormal neural tube and limb patterning. Altered patterning phenotypes in the limb and neural tube are due to perturbations in the hedgehog (Hh) signaling pathway. Motile cilia are important in fluid movement and defects in motility result in chronic respiratory infections, altered left-right asymmetry, and infertility. These features are the hallmarks of Primary Ciliary Dyskinesia (PCD, OMIM 244400). While mutations in several genes are associated with PCD in patients and animal models, the genetic lesion in many cases is unknown. We assessed the in vivo functions of Growth Arrest Specific 8 (GAS8). GAS8 shares strong sequence similarity with the Chlamydomonas Nexin-Dynein Regulatory Complex (NDRC) protein 4 (DRC4) where it is needed for proper flagella motility. In mammalian cells, the GAS8 protein localizes not only to the microtubule axoneme of motile cilia, but also to the base of non-motile cilia. Gas8 was recently implicated in the Hh signaling pathway as a regulator of Smoothened trafficking into the cilium. Here, we generate the first mouse with a Gas8 mutation and show that it causes severe PCD phenotypes; however, there were no overt Hh pathway phenotypes. In addition, we identified two human patients with missense variants in Gas8. Rescue experiments in Chlamydomonas revealed a subtle defect in swim velocity compared to controls. Further experiments using CRISPR/Cas9 homology driven repair (HDR) to generate one of these human missense variants in mice demonstrated that this allele is likely pathogenic.

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<![CDATA[Follistatin like-1 (Fstl1) is required for the normal formation of lung airway and vascular smooth muscle at birth]]> https://www.researchpad.co/article/5989db5cab0ee8fa60be02b6

Fstl1, a secreted protein of the BMP antagonist class, has been implicated in the regulation of lung development and alveolar maturation. Here we generated a Fstl1-lacZ reporter mouse line as well as a Fstl1 knockout allele. We localized Fstl1 transcript in lung smooth muscle cells and identified Fstl1 as essential regulator of lung smooth muscle formation. Deletion of Fstl1 in mice led to postnatal death as a result of respiratory failure due to multiple defects in lung development. Analysis of the mutant phenotype showed impaired airway smooth muscle (SM) manifested as smaller SM line in trachea and discontinued SM surrounding bronchi, which were associated with decreased transcriptional factors myocardin/serum response factor (SRF) and impaired differentiation of SM cells. Fstl1 knockout mice also displayed abnormal vasculature SM manifested as hyperplasia SM in pulmonary artery. This study indicates a pivotal role for Fstl1 in early stage of lung airway smooth muscle development.

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<![CDATA[Early immune responses and development of pathogenesis of avian infectious bronchitis viruses with different virulence profiles]]> https://www.researchpad.co/article/5989db52ab0ee8fa60bdc712

Avian infectious bronchitis virus (IBV) primarily replicates in epithelial cells of the upper respiratory tract of chickens, inducing both morphological and immune modulatory changes. However, the association between the local immune responses induced by IBV and the mechanisms of pathogenesis has not yet been completely elucidated. This study compared the expression profile of genes related to immune responses in tracheal samples after challenge with two Brazilian field isolates (A and B) of IBV from the same genotype, associating these responses with viral replication and with pathological changes in trachea and kidney. We detected a suppressive effect on the early activation of TLR7 pathway, followed by lower expression levels of inflammatory related genes induced by challenge with the IBV B isolate when compared to the challenge with to the IBV A isolate. Cell-mediated immune (CMI) related genes presented also lower levels of expression in tracheal samples from birds challenged with B isolate at 1dpi. Increased viral load and a higher percentage of birds with relevant lesions were observed in both tracheal and renal samples from chickens exposed to challenge with IBV B isolate. This differential pattern of early immune responses developed after challenge with IBV B isolate, related to the downregulation of TLR7, leading to insufficient pro-inflammatory response and lower CMI responses, seem to have an association with a most severe renal lesion and an enhanced capability of replication of this isolate in chicken.

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<![CDATA[Effects of two different decellularization routes on the mechanical properties of decellularized lungs]]> https://www.researchpad.co/article/5989db5cab0ee8fa60be01da

Considering the limited number of available lung donors, lung bioengineering using whole lung scaffolds has been proposed as an alternative approach to obtain lungs suitable for transplantation. However, some decellularization protocols can cause alterations on the structure, composition, or mechanical properties of the lung extracellular matrix. Therefore, the aim of this study was to compare the acellular lung mechanical properties when using two different routes through the trachea and pulmonary artery for the decellularization process. This study was performed by using the lungs excised from 30 healthy male C57BL/6 mice, which were divided into 3 groups: tracheal decellularization (TDG), perfusion decellularization (PDG), and control groups (CG). Both decellularized groups were subjected to decellularization protocol with a solution of 1% sodium dodecyl sulfate. The behaviour of mechanical properties of the acellular lungs was measured after decellularization process. Static (Est) and dynamic (Edyn) elastances were obtained by the end-inspiratory occlusion method. TDG and PDG showed reduced Est and Edyn elastances after lung decellularization. Scanning electron microscopy showed no structural changes after lung decellularization of the TDG and PDG. In conclusion, was demonstrated that there is no significant difference in the behaviour of mechanical properties and extracellular matrix of the decellularized lungs by using two different routes through the trachea and pulmonary artery.

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<![CDATA[Human Organotypic Lung Tumor Models: Suitable For Preclinical 18F-FDG PET-Imaging]]> https://www.researchpad.co/article/5989da8fab0ee8fa60b9f68f

Development of predictable in vitro tumor models is a challenging task due to the enormous complexity of tumors in vivo. The closer the resemblance of these models to human tumor characteristics, the more suitable they are for drug-development and –testing. In the present study, we generated a complex 3D lung tumor test system based on acellular rat lungs. A decellularization protocol was established preserving the architecture, important ECM components and the basement membrane of the lung. Human lung tumor cells cultured on the scaffold formed cluster and exhibited an up-regulation of the carcinoma-associated marker mucin1 as well as a reduced proliferation rate compared to respective 2D culture. Additionally, employing functional imaging with 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography (FDG-PET) these tumor cell cluster could be detected and tracked over time. This approach allowed monitoring of a targeted tyrosine kinase inhibitor treatment in the in vitro lung tumor model non-destructively. Surprisingly, FDG-PET assessment of single tumor cell cluster on the same scaffold exhibited differences in their response to therapy, indicating heterogeneity in the lung tumor model. In conclusion, our complex lung tumor test system features important characteristics of tumors and its microenvironment and allows monitoring of tumor growth and -metabolism in combination with functional imaging. In longitudinal studies, new therapeutic approaches and their long-term effects can be evaluated to adapt treatment regimes in future.

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<![CDATA[Sodium tanshinone IIA sulfonate stimulated Cl− secretion in mouse trachea]]> https://www.researchpad.co/article/5989db5cab0ee8fa60bdff67

Sodium tanshinone IIA sulfonate (STS) is a derivate of tanshinone IIA, a lipophilic compound in Salvia miltiorrhiza. This study aimed to investigate the effect of STS on ion transport in mouse tracheal epithelium and the mechanisms underlying it. Short-circuit current (Isc) was measured to evaluate the effect of STS on transepithelial ion transport. Intracellular Ca2+ imaging was performed to observe intracellular Ca2+ concentration ([Ca2+]i) changes induced by STS in primary cultured mouse tracheal epithelial cells. Results showed that the apical application of STS at mouse trachea elicited an increase of Isc, which was abrogated by atropine, an antagonist of muscarinic acetylcholine receptor (mAChR). By removing ambient Cl or applying blockers of Ca2+-activated Cl channel (CaCC), the response of STS-induced Isc was suppressed. Moreover, STS elevated the [Ca2+]i in mouse tracheal epithelial cells. As a result, STS stimulated Cl secretion in mouse tracheal epithelium via CaCC in an mAChR-dependent way. Due to the critical role of Cl secretion in airway hydration, our findings suggested that STS may be used to ameliorate the airway dehydration symptom in cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD).

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<![CDATA[Snoo and Dpp Act as Spatial and Temporal Regulators Respectively of Adult Progenitor Cells in the Drosophila Trachea]]> https://www.researchpad.co/article/5989db29ab0ee8fa60bd0eaa

Clusters of differentiated cells contributing to organ structures retain the potential to re-enter the cell cycle and replace cells lost during development or upon damage. To do so, they must be designated spatially and respond to proper activation cues. Here we show that in the case of Drosophila differentiated larval tracheal cells, progenitor potential is conferred by the spatially restricted activity of the Snoo transcription cofactor. Furthermore, Dpp signalling regulated by endocrine hormonal cues provides the temporal trigger for their activation. Finally, we elucidate the genetic network elicited by Snoo and Dpp activity. These results illustrate a regulatory mechanism that translates intrinsic potential and extrinsic cues into the facultative stem cell features of differentiated progenitors.

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<![CDATA[An Open Receptor-Binding Cavity of Hemagglutinin-Esterase-Fusion Glycoprotein from Newly-Identified Influenza D Virus: Basis for Its Broad Cell Tropism]]> https://www.researchpad.co/article/5989d9e9ab0ee8fa60b6c178

Influenza viruses cause seasonal flu each year and pandemics or epidemic sporadically, posing a major threat to public health. Recently, a new influenza D virus (IDV) was isolated from pigs and cattle. Here, we reveal that the IDV utilizes 9-O-acetylated sialic acids as its receptor for virus entry. Then, we determined the crystal structures of hemagglutinin-esterase-fusion glycoprotein (HEF) of IDV both in its free form and in complex with the receptor and enzymatic substrate analogs. The IDV HEF shows an extremely similar structural fold as the human-infecting influenza C virus (ICV) HEF. However, IDV HEF has an open receptor-binding cavity to accommodate diverse extended glycan moieties. This structural difference provides an explanation for the phenomenon that the IDV has a broad cell tropism. As IDV HEF is structurally and functionally similar to ICV HEF, our findings highlight the potential threat of the virus to public health.

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