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.