Cigarette smoke alters the proteomic profile of lung fibroblasts.

Smoking is strongly associated with diseases such as lung cancer and chronic obstructive pulmonary disease (COPD). Lung fibroblasts are crucial for the integrity of alveolar structure by producing extracellular matrix proteins which are required for attachment, structure, and function of alveolar epithelial cells. Despite the well-known association between cigarette smoke exposure and pulmonary and cardiovascular diseases, many questions remain regarding the mechanisms by which smoking induces diseases. The aim of this study is to detect differentially expressed proteins in human foetal lung cells (HFL-1) after 5 and 10% doses of cigarette smoke extract (CSE) exposure, combining two-dimensional electrophoresis (2DE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). In order to evaluate cellular ability to recover as well as lasting damage, we analysed the proteomic pattern 24 hours after the CSE removal (release). Eleven proteins had significant changes at various experimental points. Among these, 7 were up-regulated after CSE-treatments and 4 were down-regulated. Some spots seemed to be modified permanently or in a transient manner, in fact they returned to baseline levels after CSE-removal (normalisation after CSE release) and others were modified by selective CSE concentrations or only after release. MS identified, differentially expressed proteins are involved in stress response, mitochondrial activity, and aging. These findings may improve our understanding about molecular mechanisms underlying CSE caused damage and they may also integrate the comprehension of cigarette smoke effects on human health.

Persistent activation of nuclear factor-kappaB signaling pathway in severe uncontrolled asthma.

The transcription factor nuclear factor-kappaB (NF-kappaB) is inactive when bound to its inhibitory protein IkappaBalpha. On cell stimulation with inflammatory signals, IkappaBalpha is phosphorylated by IkappaB kinases and subsequently degraded. Freed NF-kappaB then induces expression of cytokines such as granulocyte-macrophage colony-stimulating factor, interleukin-8, and regulated upon activation, normal T cell expressed and secreted. These mediators are overexpressed in asthma and are downregulated by glucocorticoids through NF-kappaB activity repression. However, high levels of granulocyte-macrophage colony-stimulating factor, interleukin-8, and regulated upon activation, normal T cell expressed and presumably secreted are released by peripheral blood mononuclear cells isolated from patients with severe asthma despite continuous systemic glucocorticoid treatment. We report that these mediators are markedly decreased by pyrrolidinedithiocarbamate, an inhibitor of NF-kappaB activation. To further characterize the persistent NF-kappaB activation in severe asthma, we analyzed the expression of various components of this activation pathway in healthy subjects and in asthmatics with mild controlled, and moderate and severe uncontrolled disease. We found high amounts of phosphorylated IkappaBalpha characterizing the three asthmatic groups. Western blot analyses indicated that in peripheral blood mononuclear cells the IkappaB kinase beta and p65 levels were greater in moderate and severe asthmatics than in normal subjects. Electrophoretic mobility shift assay and immunocytochemistry showed a greater activation status of p65 in severe asthmatics. Our data suggest that exaggerated NF-kappaB activation perpetuates inflammatory mediators production in severe asthma.