Chronic IL9 and IL-13 Exposure Leads to an Altered Differentiation of Ciliated Cells in a Well-Differentiated Paediatric Bronchial Epithelial Cell Model

Asthma is a chronic inflammatory disease characterised by airways remodelling. In mouse models IL-9 and IL-13 have been implicated in airways remodelling including mucus hypersecretion and goblet cell hyperplasia. Their role, especially that of IL-9, has been much less studied in authentic human ex vivo models of the bronchial epithelium from normal and asthmatic children. We assessed the effects of IL-9, IL-13 and an IL-9/IL-13 combination, during differentiation of bronchial epithelial cells from normal (n?=?6) and asthmatic (n?=?8) children. Cultures were analysed for morphological markers and factors associated with altered differentiation (MUC5AC, SPDEF and MMP-7). IL-9, IL-9/IL-13 combination and IL-13 stimulated bronchial epithelial cells from normal children had fewer ciliated cells [14.8% (SD 8.9), p?=?0.048, 12.4 (SD 6.1), p?=?0.016 and 7.3% (SD 6.6), p?=?0.031] respectively compared with unstimulated [(21.4% (SD 9.6)]. IL-9 stimulation had no effect on goblet cell number in either group whereas IL-9/IL-13 combination and IL-13 significantly increased goblet cell number [24.8% (SD 8.8), p?=?0.02), 32.9% (SD 8.6), p?=?0.007] compared with unstimulated normal bronchial cells [(18.6% (SD 6.2)]. All stimulations increased MUC5AC mRNA in bronchial epithelial cells from normal children and increased MUC5AC mucin secretion. MMP-7 localisation was dysregulated in normal bronchial epithelium stimulated with Th2 cytokines which resembled the unstimulated bronchial epithelium of asthmatic children. All stimulations resulted in a significant reduction in transepithelial electrical resistance values over time suggesting a role in altered tight junction formation. We conclude that IL-9 does not increase goblet cell numbers in bronchial epithelial cell cultures from normal or asthmatic children. IL-9 and IL-13 alone and in combination, reduce ciliated cell numbers and transepithelial electrical resistance during differentiation of normal epithelium, which clinically could inhibit mucociliary clearance and drive an altered repair mechanism. This suggests an alternative role for IL-9 in airways remodelling and reaffirms IL-9 as a potential therapeutic target.© 2013 Parker et al.

Identification and control of Hammerstein systems via wireless networks

This paper investigates a systematic approach for the identification and control of Hammerstein systems over a physical IEEE 802.11b wireless channel.

The effect of hypoxia on propranolol clearance during antegrade and retrograde flow in the isolated perfused rat liver preparation

We investigated, using the single-pass isolated perfused rat liver preparation, whether the centrilobular location of hepatic oxidative drug metabolism could be a contributing factor to the marked sensitivity of drug oxidation to hypoxia. Livers (N = 7) were each perfused for 130 min with 2 micrograms/mL (+)-propranolol, a drug metabolized almost entirely by oxidation in the rat. The direction of flow was reversed after 60 min, the order of flow direction being randomized. Normal oxygenation was used during the first 30 min of antegrade and of retrograde perfusion, but in the second 30 min perfusate was equilibrated with a N2/O2 mixture designed to reduce hepatic oxygen delivery by half. During normal oxygenation there was no significant difference between antegrade and retrograde perfusion in hepatic oxygen delivery and physiological parameters such as oxygen consumption and extraction, perfusion pressure and bile flow. During hypoxia, mean oxygen delivery was slightly lower with retrograde perfusion (retrograde: mean = 2.37 mumol/min/g liver, range = 1.56-3.17; antegrade: mean = 2.90 mumol/min/g liver, range = 1.96-4.08; P = 0.04), but there was no significant difference in physiological parameters within each liver (P > 0.05). Propranolol clearance during normal oxygenation was similar to the perfusion rate (10 mL/min) and was the same for both directions of perfusion (antegrade 9.88 +/- 0.07 mL/min, retrograde 9.88 +/- 0.13 mL/min, P > 0.05). Hypoxia reduced propranolol clearance substantially, but the decrease was significantly greater with antegrade perfusion (5.65 +/- 1.89 mL/min) than with retrograde perfusion (6.76 +/- 1.95 mL/min, P = 0.014). Oxidative drug metabolism is located primarily in the centrilobular zone and sinusoidal oxygen concentration is lowest in the "downstream" zone with both antegrade and retrograde perfusion. These findings suggest that the centrilobular location of propranolol metabolism may influence the effect of hypoxia on propranolol elimination, but is not a major contributor to the marked sensitivity of propranolol elimination to hypoxia antegrade perfusion.

Pathogenic Yersinia enterocolitica strains increase the outer membrane permeability in response to environmental stimuli by modulating lipopolysaccharide fluidity and lipid A structure

Pathogenic biotypes of Yersinia enterocolitica (serotypes O:3, O:8, O:9, and O:13), but not environmental biotypes (serotypes O:5, O:6, O:7,8, and O:7,8,13,19), increased their permeability to hydrophobic probes when they were grown at pH 5.5 or in EGTA-supplemented (Ca(2+)-restricted) media at 37 degrees C. A similar observation was also made when representative strains of serotypes O:8 and O:5 were tested after brief contact with human monocytes. The increase in permeability was independent of the virulence plasmid. The role of lipopolysaccharide (LPS) in this phenomenon was examined by using Y. enterocolitica serotype O:8. LPS aggregates of bacteria grown in acidic or EGTA-supplemented broth took up more N-phenylnaphthylamine than LPS aggregates of bacteria grown in standard broth and also showed a marked increase in acyl chain fluidity which correlated with permeability, as determined by measurements obtained in the presence of hydrophobic dyes. No significant changes in O-antigen polymerization were observed, but lipid A acylation changed depending on the growth conditions. In standard medium at 37 degrees C, there were hexa-, penta-, and tetraacyl lipid A forms, and the pentaacyl form was dominant. The amount of tetraacyl lipid A increased in EGTA-supplemented and acidic media, and hexaacyl lipid A almost disappeared under the latter conditions. Our results suggest that pathogenic Y. enterocolitica strains modulate lipid A acylation coordinately with expression of virulence proteins, thus reducing LPS packing and increasing outer membrane permeability. The changes in permeability, LPS acyl chain fluidity, and lipid A acylation in pathogenic Y. enterocolitica strains approximate the characteristics in Yersinia pseudotuberculosis and Yersinia pestis and suggest that there is a common outer membrane pattern associated with pathogenicity.

Type-I interferons induce lung protease responses following respiratory syncytial virus infection via RIG-I-like receptors

The role of proteases in viral infection of the lung is poorly understood. Thus, we examined matrix metalloproteinases (MMPs) and cathepsin proteases in respiratory syncytial virus (RSV)-infected mouse lungs. RSV-induced gene expression for MMPs -2, -3, -7, -8, -9, -10, -12, -13, -14, -16, -17, -19, -20, -25, -27, and -28 and cathepsins B, C, E, G, H, K, L1, S, W, and Z in the airways of Friend leukemia virus B sensitive strain mice. Increased proteases were present in the bronchoalveolar lavage fluid (BALF) and lung tissue during infection. Mitochondrial antiviral-signaling protein (MAVS) and TIR-domain-containing adapter-inducing interferon-β-deficient mice were exposed to RSV. <i>Mavsi>-deficient mice had significantly lower expression of airway MMP-2, -3, -7, -8, -9, -10, -12, -13, and -28 and cathepsins C, G, K, S, W, and Z. In lung epithelial cells, retinoic acid-inducible gene-1 (RIG-I) was identified as the major RIG-I-like receptor required for RSV-induced protease expression via MAVS. Overexpression of RIG-I or treatment with interferon-β in these cells induced MMP and cathepsin gene and protein expression. The significance of RIG-1 protease induction was demonstrated by the fact that inhibiting proteases with batimastat, E64 or ribavirin prevented airway hyperresponsiveness and enhanced viral clearance in RSV-infected mice.

LYRIC/AEG-1 is targeted to different subcellular compartments by ubiquitinylation and intrinsic nuclear localization signals

PURPOSE: LYRIC/AEG-1 has been reported to influence breast cancer survival and metastases, and its altered expression has been found in a number of cancers. The cellular function of LYRIC/AEG-1 has previously been related to its subcellular distribution in cell lines. LYRIC/AEG-1 contains three uncharacterized nuclear localization signals (NLS), which may regulate its distribution and, ultimately, function in cells.

EXPERIMENTAL DESIGN: Immunohistochemistry of a human prostate tissue microarray composed of 179 prostate cancer and 24 benign samples was used to assess LYRIC/AEG-1 distribution. Green fluorescent protein-NLS fusion proteins and deletion constructs were used to show the ability of LYRIC/AEG-1 NLS to target green fluorescent protein from the cytoplasm to the nucleus. Immunoprecipitation and Western blotting were used to show posttranslational modification of LYRIC/AEG-1 NLS regions.

RESULTS: Using a prostate tissue microarray, significant changes in the distribution of LYRIC/AEG-1 were observed in prostate cancer as an increased cytoplasmic distribution in tumors compared with benign tissue. These differences were most marked in high grade and aggressive prostate cancers and were associated with decreased survival. The COOH-terminal extended NLS-3 (amino acids 546-582) is the predominant regulator of nuclear localization, whereas extended NLS-1 (amino acids 78-130) regulates its nucleolar localization. Within the extended NLS-2 region (amino acids 415-486), LYRIC/AEG-1 can be modified by ubiquitin almost exclusively within the cytoplasm.

CONCLUSIONS: Changes in LYRIC/AEG-1 subcellular distribution can predict Gleason grade and survival. Two lysine-rich regions (NLS-1 and NLS-3) can target LYRIC/AEG-1 to subcellular compartments whereas NLS-2 is modified by ubiquitin in the cytoplasm.

Effect of weather and the hybrid energy storage on the availability of standalone microgrid

This paper presents a model for availability analysis of standalone hybrid microgrid. The microgrid used in the study consists of wind, solar storage and diesel generator. Boolean driven Markov process is used to develop the availability of the system in the proposed method. By modifying the developed model, the relationship between the availability of the system with the fine (normal) weather and disturbed (stormy) weather durations are analyzed. Effects of different converter technologies on the availability of standalone microgrid were investigated and the results have shown that the availability of microgrid increased by 5.80 % when a storage system is added. On the other hand, the availability of standalone microgrid could be overestimated by 3.56 % when weather factor is neglected. In the same way 200, 500 and 1000 hours of disturbed weather durations reduced the availability of the system by 5.36%, 9.73% and 13.05 %, respectively. In addition, the hybrid energy storage cascade topology with a capacitor in the middle maximized the system availability.

Scarred limpets at hydrothermal vents: evidence of predation by deep-sea whelks

The chaotic physical and chemical environment at deep-sea hydrothermal vents has been associated with an ecosystem with few predators, arguably allowing the habitat to provide refuge for vulnerable species. The dominance of endemic limpets with thin, open-coiled shells at north Pacific vents may support this view. To test their vulnerability to predation, the incidence of healed repair scars, which are argued to reflect non-lethal encounters with predators, were examined on the shells of over 5,800 vent limpets of Lepetodrilus fucensis McLean (1988) that were collected from 13 to 18 August 1996. Three vent fields on the Juan de Fuca Ridge at ca. 2,200 m depth were sampled, two within 70 m of 47 degrees 56.87'N 129 degrees 05.91'W, and one at 47 degrees 57.85'N 129 degrees 05.15'W with the conspicuous potential limpet predators, the zoarcid fish Pachycara gymninium Anderson and Peden (1988), the galatheid crab Munidopsis alvisca Williams (1988), and the buccinid snail Buccinum thermophilum Harasewych and Kantor (2002). Limpets from the predator-rich vent were most often scarred, a significant difference created by the high incidence of scars on small (