Global gene expression profiling of guinea pig whole-lung and hindlimb muscles following long-term exposure to cigarette smoke and/or hypoxia. Cavia porcellus

Despite intense efforts the molecular understanding of this clinically important extra pulmonary manifestation is still limited. Cigarette smoking is the main risk factor for developing COPD and therefore animal chronic smoking models have been proposed for mechanistic studies and biomarker discovery. The overarching aim of our study was to assess whether GP hindlimb muscles (both oxidative and glycolytic) show a transcriptional response to these exposures, and whether such gene signatures can be correlated to the expression of lung secreted proteins. Overall design: A cross-sectional microarray study was designed. Hartley guinea pigs were divided into four groups: one group was exposed to cigarette smoking for 3 months (n=3-4); a second group was kept in normoxia for 10 weeks and subsequently placed in an hypoxic environment (12% O2) for two weeks (n=3-4); a third group (n=4) was smoke-exposed for 3 months and to chronic hypoxia the last two smoking weeks; finally a forth group (n=3-4) served as controls remaining in normoxia for the whole study period.