Induction of the interleukin 6/ signal transducer and activator of transcription pathway in the lungs of mice sub-chronically exposed to mainstream tobacco smoke

<p>Abstract</p> <p>Background</p> <p>Tobacco smoking is associated with lung cancer and other respiratory diseases. However, little is known about the global molecular changes that precede the appearance of clinically detectable symptoms. In this study, the effects of mainstream tobacco smoke (MTS) on global transcription in the mouse lung were investigated.</p> <p>Methods</p> <p>Male C57B1/CBA mice were exposed to MTS from two cigarettes daily, 5 days/week for 6 or 12 weeks. Mice were sacrificed immediately, or 6 weeks following the last cigarette. High density DNA microarrays were used to characterize global gene expression changes in whole lung. Microarray results were validated by Quantitative real-time RT-PCR. Further analysis of protein synthesis and function was carried out for a select set of genes by ELISA and Western blotting.</p> <p>Results</p> <p>Globally, seventy nine genes were significantly differentially expressed following the exposure to MTS. These genes were associated with a number of biological processes including xenobiotic metabolism, redox balance, oxidative stress and inflammation. There was no differential gene expression in mice exposed to smoke and sampled 6 weeks following the last cigarette. Moreover, cluster analysis demonstrated that these samples clustered alongside their respective controls. We observed simultaneous up-regulation of <it>interleukin 6 </it>(<it>IL-6</it>) and its antagonist, <it>suppressor of cytokine signalling </it>(<it>SOCS3</it>) mRNA following 12 weeks of MTS exposure. Analysis by ELISA and Western blotting revealed a concomitant increase in total IL-6 antigen levels and its downstream targets, including phosphorylated signal transducer and activator of transcription 3 (Stat3), basal cell-lymphoma extra large (BCL-XL) and myeloid cell leukemia 1 (MCL-1) protein, in total lung tissue extracts. However, in contrast to gene expression, a subtle decrease in total SOCS3 protein was observed after 12 weeks of MTS exposure.</p> <p>Conclusion</p> <p>Global transcriptional analysis identified a set of genes responding to MTS exposure in mouse lung. These genes returned to basal levels following smoking cessation, providing evidence to support the benefits of smoking cessation. Detailed analyses were undertaken for IL-6 and its associated pathways. Our results provide further insight into the role of these pathways in lung injury and inflammation induced by MTS.</p

Deuteron And Alpha-Particle Total Reaction Cross Sections For Nuclei With A~50

The total reaction cross sections for the target nuclei 45 Sc, 48 Ti, 51 V and 52,53,54 Cr induced by 13.6 MeV deuterons and 27.2 MeV alpha particles were measured. The deuteron-induced total reaction cross sections for 48 Ti and 52,54 Cr are well reproduced by optical-model calculations. Ambiguity of parameters for these nuclei is reduced considerably. The total reaction cross sections corresponding to alpha particles are analysed in the quasiclassical approximation. It is shown that isotopic-isotonic effects may be explained quantitatively if one assumes that the diffuseness of the nuclear density distribution for the nucleus 52 Cr is less than that for 51 V by Delta a=0.28+or-0.11 fm, and the diffuseness of the isotope 54 Cr is greater than that for 52 Cr by Delta a=0.13+or-0.11 fm. The optical-model analysis of elastic scattering and total reaction cross sections for the nuclei 45 Sc, 48 Ti and 51 V was carried out concurrently. The experimental data are explained successfully using a six-parameter optical potential