Phenotypic marker expression during fetal and neonatal differentiation of rat tracheal epithelial cells.

The expression of phenotypic markers was examined during fetal and neonatal differentiation of rat tracheal epithelial (RTE) cells. The rat counterpart of human keratin 18 was predominantly found in columnar cells in the adult trachea. It was detected in the primordial tracheal epithelium first seen on gestational day (GD) 12 (term = 21.5 days). Staining intensity gradually increased, and by GD 17 it was principally localized to the apical portion of the epithelium. The rat counterpart of human keratin 19 was barely detectable in the trachea on GD 13 but became abundant in almost all RTE cells on and after GD 19. Morphologically and immunocytochemically identifiable secretory and ciliated cells appeared on GD 18. Ciliated cell number slowly rose while secretory cells increased dramatically on GD 19 through postnatal day 1. The secretory granule antigens detected by monoclonal antibodies RTE 9 and 11 were rare in the adult trachea but were highly expressed in virtually all of the perinatal secretory cells. In contrast, the epitope detected by monoclonal antibody RTE 12, which was present in all adult tracheal surface secretory cells, did not appear until postnatal day 1 and slowly increased. These results demonstrate marked shifts in the biochemical composition of secretory cells during development and postnatal maturation. For the above-mentioned molecules, a similar expression pattern was observed during epithelial regeneration in tracheal grafts (Am. J. Respir. Cell Mol. Biol. 1992; 7:30-41). Pseudo-stratification of the epithelium and basal cells was first observed on GD 20. Keratin 14, which is confined to basal cells in the normal adult trachea, was not present in the nascent basal cells but appeared after postnatal day 1. In contrast to the present results, during epithelial regeneration in tracheal grafts keratin 14 appeared before markers of highly differentiated secretory or ciliated cells. Thus, the biochemical sequence of cellular differentiation during regeneration did not precisely recapitulate development

SERCA2 Regulates Non-CF and CF Airway Epithelial Cell Response to Ozone

Calcium mobilization can regulate a wide range of essential functions of respiratory epithelium, including ion transport, ciliary beat frequency, and secretion of mucus, all of which are modified in cystic fibrosis (CF). SERCA2, an important controller of calcium signaling, is deficient in CF epithelium. We conducted this study to determine whether SERCA2 deficiency can modulate airway epithelial responses to environmental oxidants such as ozone. This could contribute to the pathogenesis of pulmonary exacerbations, which are important and frequent clinical events in CF. To address this, we used air-liquid interface (ALI) cultures of non-CF and CF cell lines, as well as differentiated cultures of cells derived from non-CF and CF patients. We found that ozone exposure caused enhanced membrane damage, mitochondrial dysfunction and apoptotic cell death in CF airway epithelial cell lines relative to non-CF. Ozone exposure caused increased proinflammatory cytokine production in CF airway epithelial cell lines. Elevated proinflammatory cytokine production also was observed in shRNA-mediated SERCA2 knockdown cells. Overexpression of SERCA2 reversed ozone-induced proinflammatory cytokine production. Ozone-induced proinflammatory cytokine production was NF-κB- dependent. In a stable NF-κB reporter cell line, SERCA2 inhibition and knockdown both upregulated cytomix-induced NF-κB activity, indicating importance of SERCA2 in modulating NF-κB activity. In this system, increased NF-κB activity was also accompanied by increased IL-8 production. Ozone also induced NF-κB activity and IL-8 release, an effect that was greater in SERCA2-silenced NF-κB-reporter cells. SERCA2 overexpression reversed cytomix-induced increased IL-8 release and total nuclear p65 in CFTR-deficient (16HBE-AS) cells. These studies suggest that SERCA2 is an important regulator of the proinflammatory response of airway epithelial cells and could be a potential therapeutic target

Self-repair ability of evolved self-assembling systems in cellular automata

Self-repairing systems are those that are able to reconfigure themselves following disruptions to bring them back into a defined normal state. In this paper we explore the self-repair ability of some cellular automata-like systems, which differ from classical cellular automata by the introduction of a local diffusion process inspired by chemical signalling processes in biological development. The update rules in these systems are evolved using genetic programming to self-assemble towards a target pattern. In particular, we demonstrate that once the update rules have been evolved for self-assembly, many of those update rules also provide a self-repair ability without any additional evolutionary process aimed specifically at self-repair

The Structure of Spatial Localization

Material objects, such as tables and chairs, have an intimate relationship with space. They have to be somewhere. They must possess an address at which they are found. Under this aspect, they are in good company. Events, too, such as Caesar’s death and John’s buttering of the toast, and more elusive entities, such as the surface of the table, have an address, difficult as it may be to specify. A stronger notion presents itself, though. Some entities may not only be located at an address; they may also own (as it were) the place at which they are located, so as to exclude other entities from being located at the same address. Thus, for certain kinds of entities, no two tokens of the same kind can be located at the same place at the same time. This is typically the case with material objects. Likewise, no two particularized properties of the same level or degree of determinacy can be located at the same place at the same time (although particularized properties of different degree, such as the red of this table and the color of this table, can). Other entities seem to evade the restriction. Two events can be perfectly co-located without competing for their address. Or, to use a different terminology, events do not occupy the spatial region at which they are located, and can therefore share it with other events. The rotation of the Earth and the cooling down of the Earth take place at exactly the same regio

A Search for 6.7 GHz Methanol Masers in OH Megamaser Galaxies at 0.11<z<0.27

We report the results of a search for 6.7 GHz methanol (CH3OH) maser emission in OH megamaser galaxies at 0.11<z<0.27. No detections were made in the 25 objects observed down to rms noise levels of roughly 0.6 mJy in 150 kHz channels. The OH megamaser sample includes OH emission of all observed types: narrow and broad, physically compact and extended, variable and quiescent, and from simple single lines to multi-component complexes to lines with high velocity wings. Our null result indicates, for the widest possible range of OH megamaser environments, that methanol masing does not scale with OH from Galactic masers to megamasers. These observations, however, are not sensitive enough to rule out methanol masing that scales with star formation from Galactic compact HII regions to starbursts associated with major mergers. This and previous work suggest that OH megamasers do not represent large ensembles of individual masers associated with star forming regions. Maser models combined with observational constraints on the physical settings of OH megamasers indicate that 6.7 GHz methanol megamasers will not be detected by this survey if T(dust) < 100 K or if n(CH3OH) < n(OH).Comment: 5 pages, 1 figure, accepted by A

Concomitant therapy with Cineole (Eucalyptole) reduces exacerbations in COPD: A placebo-controlled double-blind trial

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Apoptosis and the activity of ceramide, Bax and Bcl-2 in the lungs of neonatal rats exposed to limited and prolonged hyperoxia

BACKGROUND: The aim of the study is to examine the effect of limited and prolonged hyperoxia on neonatal rat lung. This is done by examining the morphologic changes of apoptosis, the expression of ceramide, an important mediator of apoptosis, the expression of inflammatory mediators represented by IL-1β and the expression of 2 proto-oncogenes that appear to modulate apoptosis (Bax and Bcl-2). METHODS: Newborn rats were placed in chambers containing room air or oxygen above 90% for 7 days. The rats were sacrificed at 3, 7 or 14 days and their lungs removed. Sections were fixed, subjected to TUNEL, Hoechst, and E-Cadherin Staining. Sections were also incubated with anti-Bcl-2 and anti-Bax antisera. Bcl-2 and Bax were quantitated by immunohistochemistry. Lipids were extracted, and ceramide measured through a modified diacylglycerol kinase assay. RT-PCR was utilized to assess IL-1β expression. RESULTS: TUNEL staining showed significant apoptosis in the hyperoxia-exposed lungs at 3 days only. Co-staining of the apoptotic cells with Hoechst, and E-Cadherin indicated that apoptotic cells were mainly epithelial cells. The expression of Bax and ceramide was significantly higher in the hyperoxia-exposed lungs at 3 and 14 days of age, but not at 7 days. Bcl-2 was significantly elevated in the hyperoxia-exposed lungs at 3 and 14 days. IL-1β expression was significantly increased at 14 days. CONCLUSION: Exposure of neonatal rat lung to hyperoxia results in early apoptosis documented by TUNEL assay. The early rise in Bax and ceramide appears to overcome the anti-apoptotic activity of Bcl-2. Further exposure did not result in late apoptotic changes. This suggests that apoptotic response to hyperoxia is time sensitive. Prolonged hyperoxia results in acute lung injury and the shifting balance of ceramide, Bax and Bcl-2 may be related to the evolution of the inflammatory process